diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8efe92df8b..1c72d480b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,8 @@ Increment the:
 
 ## [Unreleased]
 
+* [API] Move class from opentelemetry::core namespace to opentelemetry::common namespace ([#686](https://github.com/open-telemetry/opentelemetry-cpp/pull/686))
+
 ## [0.4.0] 2021-04-12
 
 * [EXPORTER] ETW Exporter enhancements ([#519](https://github.com/open-telemetry/opentelemetry-cpp/pull/519))
diff --git a/api/include/opentelemetry/core/timestamp.h b/api/include/opentelemetry/common/timestamp.h
similarity index 55%
rename from api/include/opentelemetry/core/timestamp.h
rename to api/include/opentelemetry/common/timestamp.h
index c76edd76f4..b08d955407 100644
--- a/api/include/opentelemetry/core/timestamp.h
+++ b/api/include/opentelemetry/common/timestamp.h
@@ -7,26 +7,46 @@
 #include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
-namespace core
+namespace common
 {
 /**
- * Represents a timepoint relative to the system clock epoch
+ * @brief A timepoint relative to the system clock epoch.
+ *
+ * This is used for marking the beginning and end of an operation.
  */
 class SystemTimestamp
 {
 public:
+  /**
+   * @brief Initializes a system timestamp pointing to the start of the epoch.
+   */
   SystemTimestamp() noexcept : nanos_since_epoch_{0} {}
 
+  /**
+   * @brief Initializes a system timestamp from a duration.
+   *
+   * @param time_since_epoch Time elapsed since the beginning of the epoch.
+   */
   template <class Rep, class Period>
   explicit SystemTimestamp(const std::chrono::duration<Rep, Period> &time_since_epoch) noexcept
       : nanos_since_epoch_{static_cast<int64_t>(
             std::chrono::duration_cast<std::chrono::nanoseconds>(time_since_epoch).count())}
   {}
 
+  /**
+   * @brief Initializes a system timestamp based on a point in time.
+   *
+   * @param time_point A point in time.
+   */
   /*implicit*/ SystemTimestamp(const std::chrono::system_clock::time_point &time_point) noexcept
       : SystemTimestamp{time_point.time_since_epoch()}
   {}
 
+  /**
+   * @brief Returns a time point for the time stamp.
+   *
+   * @return A time point corresponding to the time stamp.
+   */
   operator std::chrono::system_clock::time_point() const noexcept
   {
     return std::chrono::system_clock::time_point{
@@ -35,18 +55,30 @@ class SystemTimestamp
   }
 
   /**
-   * @return the amount of time that has passed since the system clock epoch
+   * @brief Returns the nanoseconds since the beginning of the epoch.
+   *
+   * @return Elapsed nanoseconds since the beginning of the epoch for this timestamp.
    */
   std::chrono::nanoseconds time_since_epoch() const noexcept
   {
     return std::chrono::nanoseconds{nanos_since_epoch_};
   }
 
+  /**
+   * @brief Compare two steady time stamps.
+   *
+   * @return true if the two time stamps are equal.
+   */
   bool operator==(const SystemTimestamp &other) const noexcept
   {
     return nanos_since_epoch_ == other.nanos_since_epoch_;
   }
 
+  /**
+   * @brief Compare two steady time stamps for inequality.
+   *
+   * @return true if the two time stamps are not equal.
+   */
   bool operator!=(const SystemTimestamp &other) const noexcept
   {
     return nanos_since_epoch_ != other.nanos_since_epoch_;
@@ -57,23 +89,43 @@ class SystemTimestamp
 };
 
 /**
- * Represents a timepoint relative to the monotonic clock epoch
+ * @brief A timepoint relative to the monotonic clock epoch
+ *
+ * This is used for calculating the duration of an operation.
  */
 class SteadyTimestamp
 {
 public:
+  /**
+   * @brief Initializes a monotonic timestamp pointing to the start of the epoch.
+   */
   SteadyTimestamp() noexcept : nanos_since_epoch_{0} {}
 
+  /**
+   * @brief Initializes a monotonic timestamp from a duration.
+   *
+   * @param time_since_epoch Time elapsed since the beginning of the epoch.
+   */
   template <class Rep, class Period>
   explicit SteadyTimestamp(const std::chrono::duration<Rep, Period> &time_since_epoch) noexcept
       : nanos_since_epoch_{static_cast<int64_t>(
             std::chrono::duration_cast<std::chrono::nanoseconds>(time_since_epoch).count())}
   {}
 
+  /**
+   * @brief Initializes a monotonic timestamp based on a point in time.
+   *
+   * @param time_point A point in time.
+   */
   /*implicit*/ SteadyTimestamp(const std::chrono::steady_clock::time_point &time_point) noexcept
       : SteadyTimestamp{time_point.time_since_epoch()}
   {}
 
+  /**
+   * @brief Returns a time point for the time stamp.
+   *
+   * @return A time point corresponding to the time stamp.
+   */
   operator std::chrono::steady_clock::time_point() const noexcept
   {
     return std::chrono::steady_clock::time_point{
@@ -82,18 +134,30 @@ class SteadyTimestamp
   }
 
   /**
-   * @return the amount of time that has passed since the monotonic clock epoch
+   * @brief Returns the nanoseconds since the beginning of the epoch.
+   *
+   * @return Elapsed nanoseconds since the beginning of the epoch for this timestamp.
    */
   std::chrono::nanoseconds time_since_epoch() const noexcept
   {
     return std::chrono::nanoseconds{nanos_since_epoch_};
   }
 
+  /**
+   * @brief Compare two steady time stamps.
+   *
+   * @return true if the two time stamps are equal.
+   */
   bool operator==(const SteadyTimestamp &other) const noexcept
   {
     return nanos_since_epoch_ == other.nanos_since_epoch_;
   }
 
+  /**
+   * @brief Compare two steady time stamps for inequality.
+   *
+   * @return true if the two time stamps are not equal.
+   */
   bool operator!=(const SteadyTimestamp &other) const noexcept
   {
     return nanos_since_epoch_ != other.nanos_since_epoch_;
@@ -102,5 +166,5 @@ class SteadyTimestamp
 private:
   int64_t nanos_since_epoch_;
 };
-}  // namespace core
+}  // namespace common
 OPENTELEMETRY_END_NAMESPACE
diff --git a/api/include/opentelemetry/logs/logger.h b/api/include/opentelemetry/logs/logger.h
index 53aa6e872d..b436d96ec5 100644
--- a/api/include/opentelemetry/logs/logger.h
+++ b/api/include/opentelemetry/logs/logger.h
@@ -23,7 +23,7 @@
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/logs/severity.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/span.h"
@@ -80,7 +80,7 @@ class Logger
                    trace::TraceId trace_id,
                    trace::SpanId span_id,
                    trace::TraceFlags trace_flags,
-                   core::SystemTimestamp timestamp) noexcept = 0;
+                   common::SystemTimestamp timestamp) noexcept = 0;
 
   /*** Overloaded methods for KeyValueIterables ***/
   /**
@@ -101,7 +101,7 @@ class Logger
            trace::TraceId trace_id,
            trace::SpanId span_id,
            trace::TraceFlags trace_flags,
-           core::SystemTimestamp timestamp) noexcept
+           common::SystemTimestamp timestamp) noexcept
   {
     Log(severity, name, body, common::KeyValueIterableView<T>(resource),
         common::KeyValueIterableView<U>(attributes), trace_id, span_id, trace_flags, timestamp);
@@ -115,7 +115,7 @@ class Logger
            trace::TraceId trace_id,
            trace::SpanId span_id,
            trace::TraceFlags trace_flags,
-           core::SystemTimestamp timestamp) noexcept
+           common::SystemTimestamp timestamp) noexcept
   {
     return this->Log(severity, name, body,
                      nostd::span<const std::pair<nostd::string_view, common::AttributeValue>>{
diff --git a/api/include/opentelemetry/logs/noop.h b/api/include/opentelemetry/logs/noop.h
index 86738692c1..0f8650f277 100644
--- a/api/include/opentelemetry/logs/noop.h
+++ b/api/include/opentelemetry/logs/noop.h
@@ -24,8 +24,8 @@
 
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/context/runtime_context.h"
-#include "opentelemetry/core/timestamp.h"
 #include "opentelemetry/logs/logger.h"
 #include "opentelemetry/logs/logger_provider.h"
 #include "opentelemetry/logs/severity.h"
@@ -60,7 +60,7 @@ class NoopLogger final : public Logger
            trace::TraceId trace_id,
            trace::SpanId span_id,
            trace::TraceFlags trace_flags,
-           core::SystemTimestamp timestamp) noexcept override
+           common::SystemTimestamp timestamp) noexcept override
   {}
 };
 
diff --git a/api/include/opentelemetry/plugin/tracer.h b/api/include/opentelemetry/plugin/tracer.h
index d782d7d187..8e1dec632f 100644
--- a/api/include/opentelemetry/plugin/tracer.h
+++ b/api/include/opentelemetry/plugin/tracer.h
@@ -26,13 +26,13 @@ class Span final : public trace::Span
 
   void AddEvent(nostd::string_view name) noexcept override { span_->AddEvent(name); }
 
-  void AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) noexcept override
+  void AddEvent(nostd::string_view name, common::SystemTimestamp timestamp) noexcept override
   {
     span_->AddEvent(name, timestamp);
   }
 
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const common::KeyValueIterable &attributes) noexcept override
   {
     span_->AddEvent(name, timestamp, attributes);
diff --git a/api/include/opentelemetry/trace/default_span.h b/api/include/opentelemetry/trace/default_span.h
index 9eabba6d04..6051a72e58 100644
--- a/api/include/opentelemetry/trace/default_span.h
+++ b/api/include/opentelemetry/trace/default_span.h
@@ -23,10 +23,10 @@ class DefaultSpan : public Span
 
   void AddEvent(nostd::string_view /* name */) noexcept {}
 
-  void AddEvent(nostd::string_view /* name */, core::SystemTimestamp /* timestamp */) noexcept {}
+  void AddEvent(nostd::string_view /* name */, common::SystemTimestamp /* timestamp */) noexcept {}
 
   void AddEvent(nostd::string_view /* name */,
-                core::SystemTimestamp /* timestamp */,
+                common::SystemTimestamp /* timestamp */,
                 const common::KeyValueIterable & /* attributes */) noexcept
   {}
 
diff --git a/api/include/opentelemetry/trace/noop.h b/api/include/opentelemetry/trace/noop.h
index 3255b40adc..762b2dd035 100644
--- a/api/include/opentelemetry/trace/noop.h
+++ b/api/include/opentelemetry/trace/noop.h
@@ -35,11 +35,12 @@ class NoopSpan final : public Span
 
   void AddEvent(nostd::string_view /*name*/) noexcept override {}
 
-  void AddEvent(nostd::string_view /*name*/, core::SystemTimestamp /*timestamp*/) noexcept override
+  void AddEvent(nostd::string_view /*name*/,
+                common::SystemTimestamp /*timestamp*/) noexcept override
   {}
 
   void AddEvent(nostd::string_view /*name*/,
-                core::SystemTimestamp /*timestamp*/,
+                common::SystemTimestamp /*timestamp*/,
                 const common::KeyValueIterable & /*attributes*/) noexcept override
   {}
 
diff --git a/api/include/opentelemetry/trace/span.h b/api/include/opentelemetry/trace/span.h
index 7b020b1c6d..b9f1326853 100644
--- a/api/include/opentelemetry/trace/span.h
+++ b/api/include/opentelemetry/trace/span.h
@@ -4,7 +4,7 @@
 
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable_view.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/span.h"
 #include "opentelemetry/nostd/string_view.h"
@@ -54,8 +54,8 @@ struct StartSpanOptions
   // Span's duration, while timestamps from the system clock can be used to most
   // accurately place a Span's
   // time point relative to other Spans collected across a distributed system.
-  core::SystemTimestamp start_system_time;
-  core::SteadyTimestamp start_steady_time;
+  common::SystemTimestamp start_system_time;
+  common::SteadyTimestamp start_steady_time;
 
   // Explicitly set the parent of a Span.
   //
@@ -75,7 +75,7 @@ struct StartSpanOptions
 struct EndSpanOptions
 {
   // Optionally sets the end time of a Span.
-  core::SteadyTimestamp end_steady_time;
+  common::SteadyTimestamp end_steady_time;
 };
 
 class Tracer;
@@ -109,11 +109,11 @@ class Span
   virtual void AddEvent(nostd::string_view name) noexcept = 0;
 
   // Adds an event to the Span, with a custom timestamp.
-  virtual void AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) noexcept = 0;
+  virtual void AddEvent(nostd::string_view name, common::SystemTimestamp timestamp) noexcept = 0;
 
   // Adds an event to the Span, with a custom timestamp, and attributes.
   virtual void AddEvent(nostd::string_view name,
-                        core::SystemTimestamp timestamp,
+                        common::SystemTimestamp timestamp,
                         const common::KeyValueIterable &attributes) noexcept = 0;
 
   virtual void AddEvent(nostd::string_view name,
@@ -125,7 +125,7 @@ class Span
   template <class T,
             nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const T &attributes) noexcept
   {
     this->AddEvent(name, timestamp, common::KeyValueIterableView<T>{attributes});
@@ -139,7 +139,7 @@ class Span
   }
 
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 std::initializer_list<std::pair<nostd::string_view, common::AttributeValue>>
                     attributes) noexcept
   {
diff --git a/api/test/core/timestamp_test.cc b/api/test/core/timestamp_test.cc
index 7ea4484321..bd73d4b7bd 100644
--- a/api/test/core/timestamp_test.cc
+++ b/api/test/core/timestamp_test.cc
@@ -1,9 +1,9 @@
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 
 #include <gtest/gtest.h>
 
-using opentelemetry::core::SteadyTimestamp;
-using opentelemetry::core::SystemTimestamp;
+using opentelemetry::common::SteadyTimestamp;
+using opentelemetry::common::SystemTimestamp;
 
 template <class Timestamp>
 static bool AreNearlyEqual(const Timestamp &t1, const Timestamp &t2) noexcept
diff --git a/api/test/logs/logger_test.cc b/api/test/logs/logger_test.cc
index de03c8d403..b6c1e9edb4 100644
--- a/api/test/logs/logger_test.cc
+++ b/api/test/logs/logger_test.cc
@@ -1,7 +1,7 @@
 #include <gtest/gtest.h>
 #include <array>
 
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/logs/logger.h"
 #include "opentelemetry/logs/provider.h"
 #include "opentelemetry/nostd/shared_ptr.h"
@@ -77,7 +77,7 @@ class TestLogger : public Logger
            opentelemetry::trace::TraceId trace_id,
            opentelemetry::trace::SpanId span_id,
            opentelemetry::trace::TraceFlags trace_flags,
-           opentelemetry::core::SystemTimestamp timestamp) noexcept override
+           opentelemetry::common::SystemTimestamp timestamp) noexcept override
   {}
 };
 
diff --git a/api/test/trace/noop_test.cc b/api/test/trace/noop_test.cc
index 5d84f408e0..2b2864af1a 100644
--- a/api/test/trace/noop_test.cc
+++ b/api/test/trace/noop_test.cc
@@ -1,5 +1,5 @@
 #include "opentelemetry/trace/noop.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 
 #include <map>
 #include <memory>
@@ -7,7 +7,7 @@
 
 #include <gtest/gtest.h>
 
-using opentelemetry::core::SystemTimestamp;
+using opentelemetry::common::SystemTimestamp;
 using opentelemetry::trace::NoopTracer;
 using opentelemetry::trace::SpanContext;
 using opentelemetry::trace::Tracer;
diff --git a/examples/plugin/plugin/tracer.cc b/examples/plugin/plugin/tracer.cc
index 49170fd4a4..17cb76e704 100644
--- a/examples/plugin/plugin/tracer.cc
+++ b/examples/plugin/plugin/tracer.cc
@@ -6,7 +6,6 @@
 
 namespace nostd   = opentelemetry::nostd;
 namespace common  = opentelemetry::common;
-namespace core    = opentelemetry::core;
 namespace trace   = opentelemetry::trace;
 namespace context = opentelemetry::context;
 
@@ -34,11 +33,12 @@ class Span final : public trace::Span
 
   void AddEvent(nostd::string_view /*name*/) noexcept override {}
 
-  void AddEvent(nostd::string_view /*name*/, core::SystemTimestamp /*timestamp*/) noexcept override
+  void AddEvent(nostd::string_view /*name*/,
+                common::SystemTimestamp /*timestamp*/) noexcept override
   {}
 
   void AddEvent(nostd::string_view /*name*/,
-                core::SystemTimestamp /*timestamp*/,
+                common::SystemTimestamp /*timestamp*/,
                 const common::KeyValueIterable & /*attributes*/) noexcept override
   {}
 
diff --git a/examples/zpages/zpages_example.cc b/examples/zpages/zpages_example.cc
index 958b28132c..43fb9cd806 100644
--- a/examples/zpages/zpages_example.cc
+++ b/examples/zpages/zpages_example.cc
@@ -8,7 +8,7 @@
 
 #include "opentelemetry/ext/zpages/zpages.h"  // Required file include for zpages
 
-using opentelemetry::core::SteadyTimestamp;
+using opentelemetry::common::SteadyTimestamp;
 
 int main(int argc, char *argv[])
 {
diff --git a/exporters/elasticsearch/include/opentelemetry/exporters/elasticsearch/es_log_recordable.h b/exporters/elasticsearch/include/opentelemetry/exporters/elasticsearch/es_log_recordable.h
index 09225b9dbd..aa4836335e 100644
--- a/exporters/elasticsearch/include/opentelemetry/exporters/elasticsearch/es_log_recordable.h
+++ b/exporters/elasticsearch/include/opentelemetry/exporters/elasticsearch/es_log_recordable.h
@@ -158,7 +158,7 @@ class ElasticSearchRecordable final : public sdk::logs::Recordable
    * Set the timestamp for this log.
    * @param timestamp the timestamp of the event
    */
-  void SetTimestamp(core::SystemTimestamp timestamp) noexcept override
+  void SetTimestamp(common::SystemTimestamp timestamp) noexcept override
   {
     json_["timestamp"] = timestamp.time_since_epoch().count();
   }
diff --git a/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer.h b/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer.h
index d0cdb2c4a5..3eecec02d3 100644
--- a/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer.h
+++ b/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer.h
@@ -49,7 +49,6 @@
 #include "opentelemetry/exporters/etw/etw_provider.h"
 #include "opentelemetry/exporters/etw/utils.h"
 
-namespace core  = opentelemetry::core;
 namespace trace = opentelemetry::trace;
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -160,7 +159,7 @@ std::string GetName(T &t)
  * @return              Span Start timestamp
  */
 template <class T>
-core::SystemTimestamp GetStartTime(T &t)
+common::SystemTimestamp GetStartTime(T &t)
 {
   return t.GetStartTime();
 }
@@ -172,7 +171,7 @@ core::SystemTimestamp GetStartTime(T &t)
  * @return             Span Stop timestamp
  */
 template <class T>
-core::SystemTimestamp GetEndTime(T &t)
+common::SystemTimestamp GetEndTime(T &t)
 {
   return t.GetEndTime();
 }
@@ -625,7 +624,7 @@ class Tracer : public trace::Tracer
    */
   void AddEvent(trace::Span &span,
                 nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const common::KeyValueIterable &attributes) noexcept
   {
 #ifdef RTTI_ENABLED
@@ -652,7 +651,7 @@ class Tracer : public trace::Tracer
    */
   void AddEvent(trace::Span &span,
                 nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 Properties &evt) noexcept
   {
     // TODO: respect originating timestamp. Do we need to reserve
@@ -700,7 +699,7 @@ class Tracer : public trace::Tracer
    */
   void AddEvent(trace::Span &span,
                 nostd::string_view name,
-                core::SystemTimestamp timestamp) noexcept
+                common::SystemTimestamp timestamp) noexcept
   {
     AddEvent(span, name, timestamp, sdk::GetEmptyAttributes());
   };
@@ -734,8 +733,8 @@ class Span : public trace::Span
    */
   Properties attributes_;
 
-  core::SystemTimestamp start_time_;
-  core::SystemTimestamp end_time_;
+  common::SystemTimestamp start_time_;
+  common::SystemTimestamp end_time_;
 
   /**
    * @brief Owner Tracer of this Span
@@ -796,13 +795,13 @@ class Span : public trace::Span
    * @brief Get start time of this Span.
    * @return
    */
-  core::SystemTimestamp GetStartTime() { return start_time_; }
+  common::SystemTimestamp GetStartTime() { return start_time_; }
 
   /**
    * @brief Get end time of this Span.
    * @return
    */
-  core::SystemTimestamp GetEndTime() { return end_time_; }
+  common::SystemTimestamp GetEndTime() { return end_time_; }
 
   /**
    * @brief Get Span Name.
@@ -850,7 +849,7 @@ class Span : public trace::Span
    * @param timestamp
    * @return
    */
-  void AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) noexcept override
+  void AddEvent(nostd::string_view name, common::SystemTimestamp timestamp) noexcept override
   {
     owner_.AddEvent(*this, name, timestamp);
   }
@@ -863,7 +862,7 @@ class Span : public trace::Span
    * @return
    */
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const common::KeyValueIterable &attributes) noexcept override
   {
     owner_.AddEvent(*this, name, timestamp, attributes);
diff --git a/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer_exporter.h b/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer_exporter.h
index 107254e026..45c54a68d7 100644
--- a/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer_exporter.h
+++ b/exporters/etw/include/opentelemetry/exporters/etw/etw_tracer_exporter.h
@@ -37,5 +37,4 @@
 
 #include "opentelemetry/exporters/etw/utils.h"
 
-namespace core  = opentelemetry::core;
 namespace trace = opentelemetry::trace;
diff --git a/exporters/ostream/test/ostream_log_test.cc b/exporters/ostream/test/ostream_log_test.cc
index d6342f6128..59a06ef4f9 100644
--- a/exporters/ostream/test/ostream_log_test.cc
+++ b/exporters/ostream/test/ostream_log_test.cc
@@ -97,7 +97,7 @@ TEST(OStreamLogExporter, SimpleLogToCout)
 
   // Pass a default recordable created by the exporter to be exported
   // Create a log record and manually timestamp, severity, name, message
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
 
   auto record = std::unique_ptr<sdklogs::Recordable>(new sdklogs::LogRecord());
   record->SetTimestamp(now);
@@ -252,7 +252,7 @@ TEST(OStreamLogExporter, IntegrationTest)
   std::cout.rdbuf(stdcoutOutput.rdbuf());
 
   // Write a log to ostream exporter
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
   logger->Log(opentelemetry::logs::Severity::kDebug, "", "Hello", {}, {}, {}, {}, {}, now);
 
   // Restore cout's original streambuf
diff --git a/exporters/ostream/test/ostream_span_test.cc b/exporters/ostream/test/ostream_span_test.cc
index c955544f5c..6c7a7a1e89 100644
--- a/exporters/ostream/test/ostream_span_test.cc
+++ b/exporters/ostream/test/ostream_span_test.cc
@@ -100,7 +100,7 @@ TEST(OStreamSpanExporter, PrintSpanWithBasicFields)
 
   recordable->SetIdentity(span_context, parent_span_id);
   recordable->SetName("Test Span");
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
   recordable->SetStartTime(now);
   recordable->SetDuration(std::chrono::nanoseconds(100));
   recordable->SetStatus(opentelemetry::trace::StatusCode::kOk, "Test Description");
@@ -210,9 +210,9 @@ TEST(OStreamSpanExporter, PrintSpanWithEvents)
       new sdktrace::SimpleSpanProcessor(std::move(exporter)));
 
   auto recordable = processor->MakeRecordable();
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
-  opentelemetry::core::SystemTimestamp next(std::chrono::system_clock::now() +
-                                            std::chrono::seconds(1));
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp next(std::chrono::system_clock::now() +
+                                              std::chrono::seconds(1));
 
   std::string now_str  = std::to_string(now.time_since_epoch().count());
   std::string next_str = std::to_string(next.time_since_epoch().count());
diff --git a/exporters/otlp/include/opentelemetry/exporters/otlp/recordable.h b/exporters/otlp/include/opentelemetry/exporters/otlp/recordable.h
index b4d7fae38d..1f2d0391a9 100644
--- a/exporters/otlp/include/opentelemetry/exporters/otlp/recordable.h
+++ b/exporters/otlp/include/opentelemetry/exporters/otlp/recordable.h
@@ -26,7 +26,7 @@ class Recordable final : public sdk::trace::Recordable
                     const opentelemetry::common::AttributeValue &value) noexcept override;
 
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const common::KeyValueIterable &attributes) noexcept override;
 
   void AddLink(const opentelemetry::trace::SpanContext &span_context,
@@ -38,7 +38,7 @@ class Recordable final : public sdk::trace::Recordable
 
   void SetSpanKind(opentelemetry::trace::SpanKind span_kind) noexcept override;
 
-  void SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept override;
+  void SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept override;
 
   void SetDuration(std::chrono::nanoseconds duration) noexcept override;
 
diff --git a/exporters/otlp/src/recordable.cc b/exporters/otlp/src/recordable.cc
index b236ef125e..3e1c2443de 100644
--- a/exporters/otlp/src/recordable.cc
+++ b/exporters/otlp/src/recordable.cc
@@ -131,7 +131,7 @@ void Recordable::SetAttribute(nostd::string_view key,
 }
 
 void Recordable::AddEvent(nostd::string_view name,
-                          core::SystemTimestamp timestamp,
+                          common::SystemTimestamp timestamp,
                           const common::KeyValueIterable &attributes) noexcept
 {
   auto *event = span_.add_events();
@@ -213,7 +213,7 @@ void Recordable::SetSpanKind(opentelemetry::trace::SpanKind span_kind) noexcept
   span_.set_kind(proto_span_kind);
 }
 
-void Recordable::SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept
+void Recordable::SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept
 {
   span_.set_start_time_unix_nano(start_time.time_since_epoch().count());
 }
diff --git a/exporters/otlp/test/otlp_exporter_benchmark.cc b/exporters/otlp/test/otlp_exporter_benchmark.cc
index a72c1f5df5..76ae3871cc 100644
--- a/exporters/otlp/test/otlp_exporter_benchmark.cc
+++ b/exporters/otlp/test/otlp_exporter_benchmark.cc
@@ -87,7 +87,7 @@ void CreateSparseSpans(std::array<std::unique_ptr<sdk::trace::Recordable>, kBatc
 
     recordable->SetIdentity(kSpanContext, kParentSpanId);
     recordable->SetName("TestSpan");
-    recordable->SetStartTime(core::SystemTimestamp(std::chrono::system_clock::now()));
+    recordable->SetStartTime(common::SystemTimestamp(std::chrono::system_clock::now()));
     recordable->SetDuration(std::chrono::nanoseconds(10));
 
     recordables[i] = std::move(recordable);
@@ -103,7 +103,7 @@ void CreateDenseSpans(std::array<std::unique_ptr<sdk::trace::Recordable>, kBatch
 
     recordable->SetIdentity(kSpanContext, kParentSpanId);
     recordable->SetName("TestSpan");
-    recordable->SetStartTime(core::SystemTimestamp(std::chrono::system_clock::now()));
+    recordable->SetStartTime(common::SystemTimestamp(std::chrono::system_clock::now()));
     recordable->SetDuration(std::chrono::nanoseconds(10));
 
     for (int i = 0; i < kNumAttributes; i++)
diff --git a/exporters/otlp/test/recordable_test.cc b/exporters/otlp/test/recordable_test.cc
index 007c7359e2..5ea4e03031 100644
--- a/exporters/otlp/test/recordable_test.cc
+++ b/exporters/otlp/test/recordable_test.cc
@@ -54,7 +54,7 @@ TEST(Recordable, SetStartTime)
 {
   Recordable rec;
   std::chrono::system_clock::time_point start_time = std::chrono::system_clock::now();
-  core::SystemTimestamp start_timestamp(start_time);
+  common::SystemTimestamp start_timestamp(start_time);
 
   uint64_t unix_start =
       std::chrono::duration_cast<std::chrono::nanoseconds>(start_time.time_since_epoch()).count();
@@ -67,7 +67,7 @@ TEST(Recordable, SetDuration)
 {
   Recordable rec;
   // Start time is 0
-  core::SystemTimestamp start_timestamp;
+  common::SystemTimestamp start_timestamp;
 
   std::chrono::nanoseconds duration(10);
   uint64_t unix_end = duration.count();
@@ -95,7 +95,7 @@ TEST(Recordable, AddEventDefault)
   nostd::string_view name = "Test Event";
 
   std::chrono::system_clock::time_point event_time = std::chrono::system_clock::now();
-  core::SystemTimestamp event_timestamp(event_time);
+  common::SystemTimestamp event_timestamp(event_time);
 
   rec.sdk::trace::Recordable::AddEvent(name, event_timestamp);
 
diff --git a/exporters/zipkin/include/opentelemetry/exporters/zipkin/recordable.h b/exporters/zipkin/include/opentelemetry/exporters/zipkin/recordable.h
index f72dc4414f..3e4fbfa715 100644
--- a/exporters/zipkin/include/opentelemetry/exporters/zipkin/recordable.h
+++ b/exporters/zipkin/include/opentelemetry/exporters/zipkin/recordable.h
@@ -45,7 +45,7 @@ class Recordable final : public sdk::trace::Recordable
                     const opentelemetry::common::AttributeValue &value) noexcept override;
 
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                common::SystemTimestamp timestamp,
                 const common::KeyValueIterable &attributes) noexcept override;
 
   void AddLink(const opentelemetry::trace::SpanContext &span_context,
@@ -55,7 +55,7 @@ class Recordable final : public sdk::trace::Recordable
 
   void SetName(nostd::string_view name) noexcept override;
 
-  void SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept override;
+  void SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept override;
 
   virtual void SetSpanKind(opentelemetry::trace::SpanKind span_kind) noexcept override;
 
diff --git a/exporters/zipkin/src/recordable.cc b/exporters/zipkin/src/recordable.cc
index 14d9c1fafc..ae2e450012 100644
--- a/exporters/zipkin/src/recordable.cc
+++ b/exporters/zipkin/src/recordable.cc
@@ -159,7 +159,7 @@ void Recordable::SetAttribute(nostd::string_view key,
 }
 
 void Recordable::AddEvent(nostd::string_view name,
-                          core::SystemTimestamp timestamp,
+                          common::SystemTimestamp timestamp,
                           const common::KeyValueIterable &attributes) noexcept
 {
   nlohmann::json attrs = nlohmann::json::object();  // empty object
@@ -204,7 +204,7 @@ void Recordable::SetName(nostd::string_view name) noexcept
   span_["name"] = name.data();
 }
 
-void Recordable::SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept
+void Recordable::SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept
 {
   span_["timestamp"] =
       std::chrono::duration_cast<std::chrono::microseconds>(start_time.time_since_epoch()).count();
diff --git a/exporters/zipkin/test/zipkin_recordable_test.cc b/exporters/zipkin/test/zipkin_recordable_test.cc
index 0e8a132c1d..de124fd15f 100644
--- a/exporters/zipkin/test/zipkin_recordable_test.cc
+++ b/exporters/zipkin/test/zipkin_recordable_test.cc
@@ -22,7 +22,7 @@
 
 #include "opentelemetry/sdk/trace/exporter.h"
 
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/exporters/zipkin/recordable.h"
 
 #include <iostream>
@@ -71,7 +71,7 @@ TEST(ZipkinSpanRecordable, SetStartTime)
 {
   opentelemetry::exporter::zipkin::Recordable rec;
   std::chrono::system_clock::time_point start_time = std::chrono::system_clock::now();
-  opentelemetry::core::SystemTimestamp start_timestamp(start_time);
+  opentelemetry::common::SystemTimestamp start_timestamp(start_time);
 
   uint64_t unix_start =
       std::chrono::duration_cast<std::chrono::microseconds>(start_time.time_since_epoch()).count();
@@ -85,7 +85,7 @@ TEST(ZipkinSpanRecordable, SetDuration)
   json j_span = {{"duration", 10}, {"timestamp", 0}};
   opentelemetry::exporter::zipkin::Recordable rec;
   // Start time is 0
-  opentelemetry::core::SystemTimestamp start_timestamp;
+  opentelemetry::common::SystemTimestamp start_timestamp;
 
   std::chrono::nanoseconds duration(10);
   uint64_t unix_end = duration.count();
@@ -120,7 +120,7 @@ TEST(ZipkinSpanRecordable, AddEventDefault)
   nostd::string_view name = "Test Event";
 
   std::chrono::system_clock::time_point event_time = std::chrono::system_clock::now();
-  opentelemetry::core::SystemTimestamp event_timestamp(event_time);
+  opentelemetry::common::SystemTimestamp event_timestamp(event_time);
 
   rec.opentelemetry::sdk::trace::Recordable::AddEvent(name, event_timestamp);
 
@@ -139,7 +139,7 @@ TEST(ZipkinSpanRecordable, AddEventWithAttributes)
   nostd::string_view name = "Test Event";
 
   std::chrono::system_clock::time_point event_time = std::chrono::system_clock::now();
-  opentelemetry::core::SystemTimestamp event_timestamp(event_time);
+  opentelemetry::common::SystemTimestamp event_timestamp(event_time);
   uint64_t unix_event_time =
       std::chrono::duration_cast<std::chrono::milliseconds>(event_time.time_since_epoch()).count();
 
diff --git a/ext/include/opentelemetry/ext/zpages/threadsafe_span_data.h b/ext/include/opentelemetry/ext/zpages/threadsafe_span_data.h
index 0d3b0488a1..c2b092bb1e 100644
--- a/ext/include/opentelemetry/ext/zpages/threadsafe_span_data.h
+++ b/ext/include/opentelemetry/ext/zpages/threadsafe_span_data.h
@@ -5,7 +5,7 @@
 #include <unordered_map>
 #include <vector>
 
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/sdk/trace/recordable.h"
 #include "opentelemetry/sdk/trace/span_data.h"
@@ -100,7 +100,7 @@ class ThreadsafeSpanData final : public opentelemetry::sdk::trace::Recordable
    * Get the start time for this span
    * @return the start time for this span
    */
-  opentelemetry::core::SystemTimestamp GetStartTime() const noexcept
+  opentelemetry::common::SystemTimestamp GetStartTime() const noexcept
   {
     std::lock_guard<std::mutex> lock(mutex_);
     return start_time_;
@@ -160,7 +160,7 @@ class ThreadsafeSpanData final : public opentelemetry::sdk::trace::Recordable
     span_kind_ = span_kind;
   }
 
-  void SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept override
+  void SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept override
   {
     std::lock_guard<std::mutex> lock(mutex_);
     start_time_ = start_time;
@@ -184,7 +184,7 @@ class ThreadsafeSpanData final : public opentelemetry::sdk::trace::Recordable
 
   void AddEvent(
       nostd::string_view name,
-      core::SystemTimestamp timestamp = core::SystemTimestamp(std::chrono::system_clock::now()),
+      common::SystemTimestamp timestamp = common::SystemTimestamp(std::chrono::system_clock::now()),
       const opentelemetry::common::KeyValueIterable &attributes =
           opentelemetry::common::KeyValueIterableView<std::map<std::string, int>>(
               {})) noexcept override
@@ -218,7 +218,7 @@ class ThreadsafeSpanData final : public opentelemetry::sdk::trace::Recordable
   mutable std::mutex mutex_;
   opentelemetry::trace::SpanContext span_context_{false, false};
   opentelemetry::trace::SpanId parent_span_id_;
-  core::SystemTimestamp start_time_;
+  common::SystemTimestamp start_time_;
   std::chrono::nanoseconds duration_{0};
   std::string name_;
   opentelemetry::trace::SpanKind span_kind_;
diff --git a/ext/test/zpages/threadsafe_span_data_test.cc b/ext/test/zpages/threadsafe_span_data_test.cc
index ed9509017b..73feaf137c 100644
--- a/ext/test/zpages/threadsafe_span_data_test.cc
+++ b/ext/test/zpages/threadsafe_span_data_test.cc
@@ -41,7 +41,7 @@ TEST(ThreadsafeSpanData, Set)
       trace_id, span_id,
       opentelemetry::trace::TraceFlags{opentelemetry::trace::TraceFlags::kIsSampled}, true,
       trace_state};
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
 
   ThreadsafeSpanData data;
   data.SetIdentity(span_context, parent_span_id);
diff --git a/ext/test/zpages/tracez_data_aggregator_test.cc b/ext/test/zpages/tracez_data_aggregator_test.cc
index 324cf0c612..f6f5ba6d9f 100644
--- a/ext/test/zpages/tracez_data_aggregator_test.cc
+++ b/ext/test/zpages/tracez_data_aggregator_test.cc
@@ -11,7 +11,7 @@ using namespace opentelemetry::sdk::trace;
 using namespace opentelemetry::ext::zpages;
 namespace nostd  = opentelemetry::nostd;
 namespace common = opentelemetry::common;
-using opentelemetry::core::SteadyTimestamp;
+using opentelemetry::common::SteadyTimestamp;
 using opentelemetry::v0::trace::Span;
 
 const std::string span_name1 = "span 1";
diff --git a/sdk/include/opentelemetry/sdk/logs/log_record.h b/sdk/include/opentelemetry/sdk/logs/log_record.h
index 65030c8a57..a41e47523b 100644
--- a/sdk/include/opentelemetry/sdk/logs/log_record.h
+++ b/sdk/include/opentelemetry/sdk/logs/log_record.h
@@ -47,7 +47,7 @@ class LogRecord final : public Recordable
   opentelemetry::trace::TraceId trace_id_;
   opentelemetry::trace::SpanId span_id_;
   opentelemetry::trace::TraceFlags trace_flags_;
-  core::SystemTimestamp timestamp_;  // uint64 nanoseconds since Unix epoch
+  opentelemetry::common::SystemTimestamp timestamp_;  // uint64 nanoseconds since Unix epoch
 
 public:
   /********** Setters for each field (overrides methods from the Recordable interface) ************/
@@ -127,7 +127,10 @@ class LogRecord final : public Recordable
    * Set the timestamp for this log.
    * @param timestamp the timestamp of the event
    */
-  void SetTimestamp(core::SystemTimestamp timestamp) noexcept override { timestamp_ = timestamp; }
+  void SetTimestamp(opentelemetry::common::SystemTimestamp timestamp) noexcept override
+  {
+    timestamp_ = timestamp;
+  }
 
   /************************** Getters for each field ****************************/
 
@@ -189,7 +192,7 @@ class LogRecord final : public Recordable
    * Get the timestamp for this log
    * @return the timestamp for this log
    */
-  core::SystemTimestamp GetTimestamp() const noexcept { return timestamp_; }
+  opentelemetry::common::SystemTimestamp GetTimestamp() const noexcept { return timestamp_; }
 };
 }  // namespace logs
 }  // namespace sdk
diff --git a/sdk/include/opentelemetry/sdk/logs/logger.h b/sdk/include/opentelemetry/sdk/logs/logger.h
index 3b2c34fcb6..5666d954d2 100644
--- a/sdk/include/opentelemetry/sdk/logs/logger.h
+++ b/sdk/include/opentelemetry/sdk/logs/logger.h
@@ -67,7 +67,7 @@ class Logger final : public opentelemetry::logs::Logger
            trace::TraceId trace_id,
            trace::SpanId span_id,
            trace::TraceFlags trace_flags,
-           core::SystemTimestamp timestamp) noexcept override;
+           opentelemetry::common::SystemTimestamp timestamp) noexcept override;
 
 private:
   // The name of this logger
diff --git a/sdk/include/opentelemetry/sdk/logs/recordable.h b/sdk/include/opentelemetry/sdk/logs/recordable.h
index 45ad3eaf59..bf305ed3fa 100644
--- a/sdk/include/opentelemetry/sdk/logs/recordable.h
+++ b/sdk/include/opentelemetry/sdk/logs/recordable.h
@@ -2,7 +2,7 @@
 
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/logs/severity.h"
 #include "opentelemetry/trace/span.h"
 #include "opentelemetry/trace/span_context.h"
@@ -32,7 +32,7 @@ class Recordable
    * Set the timestamp for this log.
    * @param timestamp the timestamp to set
    */
-  virtual void SetTimestamp(core::SystemTimestamp timestamp) noexcept = 0;
+  virtual void SetTimestamp(opentelemetry::common::SystemTimestamp timestamp) noexcept = 0;
 
   /**
    * Set the severity for this log.
diff --git a/sdk/include/opentelemetry/sdk/metrics/aggregator/aggregator.h b/sdk/include/opentelemetry/sdk/metrics/aggregator/aggregator.h
index f90f1d7b5a..d3e878d785 100644
--- a/sdk/include/opentelemetry/sdk/metrics/aggregator/aggregator.h
+++ b/sdk/include/opentelemetry/sdk/metrics/aggregator/aggregator.h
@@ -2,7 +2,7 @@
 
 #include <mutex>
 #include <vector>
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/metrics/instrument.h"
 #include "opentelemetry/version.h"
 
@@ -124,7 +124,10 @@ class Aggregator
   virtual size_t get_max_buckets() { return 0; }
 
   // virtual function to be overridden for Gauge Aggregator
-  virtual core::SystemTimestamp get_checkpoint_timestamp() { return core::SystemTimestamp(); }
+  virtual opentelemetry::common::SystemTimestamp get_checkpoint_timestamp()
+  {
+    return opentelemetry::common::SystemTimestamp();
+  }
 
   // Custom copy constructor to handle the mutex
   Aggregator(const Aggregator &cp)
diff --git a/sdk/include/opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h b/sdk/include/opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h
index 5046928bac..fa36f07981 100644
--- a/sdk/include/opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h
+++ b/sdk/include/opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/metrics/instrument.h"
 #include "opentelemetry/sdk/metrics/aggregator/aggregator.h"
 #include "opentelemetry/version.h"
@@ -36,7 +36,7 @@ class GaugeAggregator : public Aggregator<T>
     this->values_      = std::vector<T>(1, 0);
     this->checkpoint_  = this->values_;
     this->agg_kind_    = AggregatorKind::Gauge;
-    current_timestamp_ = core::SystemTimestamp(std::chrono::system_clock::now());
+    current_timestamp_ = opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now());
   }
 
   ~GaugeAggregator() = default;
@@ -61,7 +61,7 @@ class GaugeAggregator : public Aggregator<T>
     this->mu_.lock();
     this->updated_     = true;
     this->values_[0]   = val;
-    current_timestamp_ = core::SystemTimestamp(std::chrono::system_clock::now());
+    current_timestamp_ = opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now());
     this->mu_.unlock();
   }
 
@@ -82,7 +82,7 @@ class GaugeAggregator : public Aggregator<T>
     // Reset the values to default
     this->values_[0]      = 0;
     checkpoint_timestamp_ = current_timestamp_;
-    current_timestamp_    = core::SystemTimestamp(std::chrono::system_clock::now());
+    current_timestamp_ = opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now());
 
     this->mu_.unlock();
   }
@@ -101,7 +101,7 @@ class GaugeAggregator : public Aggregator<T>
       this->values_[0] = other.values_[0];
       // Now merge checkpoints
       this->checkpoint_[0] = other.checkpoint_[0];
-      current_timestamp_   = core::SystemTimestamp(std::chrono::system_clock::now());
+      current_timestamp_ = opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now());
       this->mu_.unlock();
     }
     else
@@ -119,7 +119,10 @@ class GaugeAggregator : public Aggregator<T>
   /**
    * @return the latest checkpointed timestamp
    */
-  core::SystemTimestamp get_checkpoint_timestamp() override { return checkpoint_timestamp_; }
+  opentelemetry::common::SystemTimestamp get_checkpoint_timestamp() override
+  {
+    return checkpoint_timestamp_;
+  }
 
   /**
    * @return the values_ vector stored in this aggregator
@@ -129,11 +132,11 @@ class GaugeAggregator : public Aggregator<T>
   /**
    * @return the timestamp of when the last value recorded
    */
-  core::SystemTimestamp get_timestamp() { return current_timestamp_; }
+  opentelemetry::common::SystemTimestamp get_timestamp() { return current_timestamp_; }
 
 private:
-  core::SystemTimestamp current_timestamp_;
-  core::SystemTimestamp checkpoint_timestamp_;
+  opentelemetry::common::SystemTimestamp current_timestamp_;
+  opentelemetry::common::SystemTimestamp checkpoint_timestamp_;
 };
 }  // namespace metrics
 }  // namespace sdk
diff --git a/sdk/include/opentelemetry/sdk/trace/recordable.h b/sdk/include/opentelemetry/sdk/trace/recordable.h
index ef5678d921..24bca38e3f 100644
--- a/sdk/include/opentelemetry/sdk/trace/recordable.h
+++ b/sdk/include/opentelemetry/sdk/trace/recordable.h
@@ -2,7 +2,7 @@
 
 #include "opentelemetry/common/attribute_value.h"
 #include "opentelemetry/common/key_value_iterable.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/sdk/common/empty_attributes.h"
 #include "opentelemetry/trace/canonical_code.h"
@@ -54,7 +54,7 @@ class Recordable
    * @param attributes the attributes associated with the event
    */
   virtual void AddEvent(nostd::string_view name,
-                        core::SystemTimestamp timestamp,
+                        opentelemetry::common::SystemTimestamp timestamp,
                         const opentelemetry::common::KeyValueIterable &attributes) noexcept = 0;
 
   /**
@@ -63,7 +63,7 @@ class Recordable
    */
   void AddEvent(nostd::string_view name)
   {
-    AddEvent(name, core::SystemTimestamp(std::chrono::system_clock::now()),
+    AddEvent(name, opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now()),
              opentelemetry::sdk::GetEmptyAttributes());
   }
 
@@ -72,7 +72,7 @@ class Recordable
    * @param name the name of the event
    * @param timestamp the timestamp of the event
    */
-  void AddEvent(nostd::string_view name, core::SystemTimestamp timestamp)
+  void AddEvent(nostd::string_view name, opentelemetry::common::SystemTimestamp timestamp)
   {
     AddEvent(name, timestamp, opentelemetry::sdk::GetEmptyAttributes());
   }
@@ -118,7 +118,7 @@ class Recordable
    * Set the start time of the span.
    * @param start_time the start time to set
    */
-  virtual void SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept = 0;
+  virtual void SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept = 0;
 
   /**
    * Set the duration of the span.
diff --git a/sdk/include/opentelemetry/sdk/trace/span_data.h b/sdk/include/opentelemetry/sdk/trace/span_data.h
index 6eca905583..4bc7ab8dda 100644
--- a/sdk/include/opentelemetry/sdk/trace/span_data.h
+++ b/sdk/include/opentelemetry/sdk/trace/span_data.h
@@ -4,7 +4,7 @@
 #include <unordered_map>
 #include <vector>
 #include "opentelemetry/common/attribute_value.h"
-#include "opentelemetry/core/timestamp.h"
+#include "opentelemetry/common/timestamp.h"
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/sdk/common/attribute_utils.h"
 #include "opentelemetry/sdk/trace/recordable.h"
@@ -27,7 +27,7 @@ class SpanDataEvent
 {
 public:
   SpanDataEvent(std::string name,
-                core::SystemTimestamp timestamp,
+                opentelemetry::common::SystemTimestamp timestamp,
                 const opentelemetry::common::KeyValueIterable &attributes)
       : name_(name), timestamp_(timestamp), attribute_map_(attributes)
   {}
@@ -42,7 +42,7 @@ class SpanDataEvent
    * Get the timestamp for this event
    * @return the timestamp for this event
    */
-  core::SystemTimestamp GetTimestamp() const noexcept { return timestamp_; }
+  opentelemetry::common::SystemTimestamp GetTimestamp() const noexcept { return timestamp_; }
 
   /**
    * Get the attributes for this event
@@ -55,7 +55,7 @@ class SpanDataEvent
 
 private:
   std::string name_;
-  core::SystemTimestamp timestamp_;
+  opentelemetry::common::SystemTimestamp timestamp_;
   common::AttributeMap attribute_map_;
 };
 
@@ -148,7 +148,7 @@ class SpanData final : public Recordable
    * Get the start time for this span
    * @return the start time for this span
    */
-  opentelemetry::core::SystemTimestamp GetStartTime() const noexcept { return start_time_; }
+  opentelemetry::common::SystemTimestamp GetStartTime() const noexcept { return start_time_; }
 
   /**
    * Get the duration for this span
@@ -190,12 +190,12 @@ class SpanData final : public Recordable
     attribute_map_.SetAttribute(key, value);
   }
 
-  void AddEvent(
-      nostd::string_view name,
-      core::SystemTimestamp timestamp = core::SystemTimestamp(std::chrono::system_clock::now()),
-      const opentelemetry::common::KeyValueIterable &attributes =
-          opentelemetry::common::KeyValueIterableView<std::map<std::string, int>>(
-              {})) noexcept override
+  void AddEvent(nostd::string_view name,
+                opentelemetry::common::SystemTimestamp timestamp =
+                    opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now()),
+                const opentelemetry::common::KeyValueIterable &attributes =
+                    opentelemetry::common::KeyValueIterableView<std::map<std::string, int>>(
+                        {})) noexcept override
   {
     SpanDataEvent event(std::string(name), timestamp, attributes);
     events_.push_back(event);
@@ -225,7 +225,7 @@ class SpanData final : public Recordable
     span_kind_ = span_kind;
   }
 
-  void SetStartTime(opentelemetry::core::SystemTimestamp start_time) noexcept override
+  void SetStartTime(opentelemetry::common::SystemTimestamp start_time) noexcept override
   {
     start_time_ = start_time;
   }
@@ -235,7 +235,7 @@ class SpanData final : public Recordable
 private:
   opentelemetry::trace::SpanContext span_context_{false, false};
   opentelemetry::trace::SpanId parent_span_id_;
-  core::SystemTimestamp start_time_;
+  opentelemetry::common::SystemTimestamp start_time_;
   std::chrono::nanoseconds duration_{0};
   std::string name_;
   opentelemetry::trace::StatusCode status_code_{opentelemetry::trace::StatusCode::kUnset};
diff --git a/sdk/src/logs/logger.cc b/sdk/src/logs/logger.cc
index 0808f5a8e1..b4dfefb983 100644
--- a/sdk/src/logs/logger.cc
+++ b/sdk/src/logs/logger.cc
@@ -45,7 +45,7 @@ void Logger::Log(opentelemetry::logs::Severity severity,
                  opentelemetry::trace::TraceId trace_id,
                  opentelemetry::trace::SpanId span_id,
                  opentelemetry::trace::TraceFlags trace_flags,
-                 core::SystemTimestamp timestamp) noexcept
+                 opentelemetry::common::SystemTimestamp timestamp) noexcept
 {
   // If this logger does not have a processor, no need to create a log record
   auto processor = logger_provider_.lock()->GetProcessor();
diff --git a/sdk/src/trace/span.cc b/sdk/src/trace/span.cc
index caffc733bd..f890f9b9cd 100644
--- a/sdk/src/trace/span.cc
+++ b/sdk/src/trace/span.cc
@@ -11,8 +11,8 @@ namespace sdk
 namespace trace
 {
 
-using opentelemetry::core::SteadyTimestamp;
-using opentelemetry::core::SystemTimestamp;
+using opentelemetry::common::SteadyTimestamp;
+using opentelemetry::common::SystemTimestamp;
 
 namespace
 {
@@ -129,7 +129,7 @@ void Span::AddEvent(nostd::string_view name) noexcept
   recordable_->AddEvent(name);
 }
 
-void Span::AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) noexcept
+void Span::AddEvent(nostd::string_view name, SystemTimestamp timestamp) noexcept
 {
   std::lock_guard<std::mutex> lock_guard{mu_};
   if (recordable_ == nullptr)
@@ -140,7 +140,7 @@ void Span::AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) no
 }
 
 void Span::AddEvent(nostd::string_view name,
-                    core::SystemTimestamp timestamp,
+                    SystemTimestamp timestamp,
                     const opentelemetry::common::KeyValueIterable &attributes) noexcept
 {
   std::lock_guard<std::mutex> lock_guard{mu_};
diff --git a/sdk/src/trace/span.h b/sdk/src/trace/span.h
index efc16d6c59..decb2d89c9 100644
--- a/sdk/src/trace/span.h
+++ b/sdk/src/trace/span.h
@@ -33,10 +33,11 @@ class Span final : public trace_api::Span
 
   void AddEvent(nostd::string_view name) noexcept override;
 
-  void AddEvent(nostd::string_view name, core::SystemTimestamp timestamp) noexcept override;
+  void AddEvent(nostd::string_view name,
+                opentelemetry::common::SystemTimestamp timestamp) noexcept override;
 
   void AddEvent(nostd::string_view name,
-                core::SystemTimestamp timestamp,
+                opentelemetry::common::SystemTimestamp timestamp,
                 const opentelemetry::common::KeyValueIterable &attributes) noexcept override;
 
   void SetStatus(trace_api::StatusCode code, nostd::string_view description) noexcept override;
@@ -53,7 +54,7 @@ class Span final : public trace_api::Span
   std::shared_ptr<Tracer> tracer_;
   mutable std::mutex mu_;
   std::unique_ptr<Recordable> recordable_;
-  opentelemetry::core::SteadyTimestamp start_steady_time;
+  opentelemetry::common::SteadyTimestamp start_steady_time;
   std::unique_ptr<trace_api::SpanContext> span_context_;
   bool has_ended_;
 };
diff --git a/sdk/test/logs/log_record_test.cc b/sdk/test/logs/log_record_test.cc
index 774e726c54..fc4307223c 100644
--- a/sdk/test/logs/log_record_test.cc
+++ b/sdk/test/logs/log_record_test.cc
@@ -32,7 +32,7 @@ TEST(LogRecord, SetAndGet)
   opentelemetry::trace::TraceId trace_id;
   opentelemetry::trace::SpanId span_id;
   opentelemetry::trace::TraceFlags trace_flags;
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
 
   // Set all fields of the LogRecord
   LogRecord record;
diff --git a/sdk/test/trace/span_data_test.cc b/sdk/test/trace/span_data_test.cc
index 0a528987df..da4a31bd8e 100644
--- a/sdk/test/trace/span_data_test.cc
+++ b/sdk/test/trace/span_data_test.cc
@@ -40,7 +40,7 @@ TEST(SpanData, Set)
       trace_id, span_id,
       opentelemetry::trace::TraceFlags{opentelemetry::trace::TraceFlags::kIsSampled}, true,
       trace_state};
-  opentelemetry::core::SystemTimestamp now(std::chrono::system_clock::now());
+  opentelemetry::common::SystemTimestamp now(std::chrono::system_clock::now());
 
   SpanData data;
   data.SetIdentity(span_context, parent_span_id);
diff --git a/sdk/test/trace/tracer_test.cc b/sdk/test/trace/tracer_test.cc
index dbfa3146f3..2fa064d4bf 100644
--- a/sdk/test/trace/tracer_test.cc
+++ b/sdk/test/trace/tracer_test.cc
@@ -11,8 +11,8 @@
 
 using namespace opentelemetry::sdk::trace;
 using namespace opentelemetry::sdk::resource;
-using opentelemetry::core::SteadyTimestamp;
-using opentelemetry::core::SystemTimestamp;
+using opentelemetry::common::SteadyTimestamp;
+using opentelemetry::common::SystemTimestamp;
 namespace nostd  = opentelemetry::nostd;
 namespace common = opentelemetry::common;
 using opentelemetry::common::KeyValueIterableView;