diff --git a/README.md b/README.md
index 1e89a13..561d5a3 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Macros expanding into code that can be safely used in guard clauses.
 Update your `mix.exs` file and run `mix deps.get`.
 ```elixir
 defp deps do
-  [{:guardsafe, "~> 0.3.1"}]
+  [{:guardsafe, "~> 0.4.0"}]
 end
 ```
 
@@ -71,6 +71,14 @@ than `Kernel` you need to require it before use, e.g. `require Integer`.
 * `divisible_by?/2` - checks whether two integers are evenly divisible.
 * `even?/1` - returns true for even integers.
 * `odd?/1` - returns true for odd integers.
+* `within?/3` - checks whether a value is in the range of the last two arguments.
+
+#### Macros for dates and times
+* `date?/1` - checks if the term is an Erlang-style date tuple.
+* `datetime?/1` - checks if the term is an Erlang-style datetime tuple.
+* `time?/1` - checks if the term is an Erlang-style time tuple.
+
+_These can come in handy when working with a library such as [GoodTimes](https://github.com/magplus/good_times)._
 
 ### Why nil? and float? instead of is_nil and is_float
 
diff --git a/lib/guardsafe.ex b/lib/guardsafe.ex
index da5a1bb..35427d3 100644
--- a/lib/guardsafe.ex
+++ b/lib/guardsafe.ex
@@ -1,5 +1,5 @@
 defmodule Guardsafe do
-  @vsn "0.3.1"
+  @vsn "0.4.0"
   @doc false
   def version, do: @vsn
 
diff --git a/mix.exs b/mix.exs
index 11d1db7..17f5819 100644
--- a/mix.exs
+++ b/mix.exs
@@ -4,7 +4,7 @@ defmodule Guardsafe.Mixfile do
   def project do
     [
       app: :guardsafe,
-      version: "0.3.1",
+      version: "0.4.0",
       name: "Guardsafe",
       source_url: "https://github.com/DevL/guardsafe",
       homepage_url: "https://hex.pm/packages/guardsafe",