If --event-time-end is not specififed, ensure --event-time-start …

…is less than the current time

core/dbt/cli/params.py

@@ -1,3 +1,4 @@
+from datetime import datetime
 from functools import update_wrapper
 from pathlib import Path
 
@@ -744,14 +745,18 @@ def wrapper(*args, **kwargs):
         ctx = args[0]
         assert isinstance(ctx, click.Context)
 
-        if (
-            ctx.params.get("event_time_start") is not None
-            and ctx.params.get("event_time_end") is not None
-        ):
-            if ctx.params.get("event_time_start") >= ctx.params.get("event_time_end"):
+        event_time_start = ctx.params.get("event_time_start")
+        if event_time_start is not None:
+            event_time_end = ctx.params.get("event_time_end")
+
+            if event_time_end is not None and event_time_start >= event_time_end:
                 raise DbtRuntimeError(
                     "Value for `--event-time-end` must be less than `--event-time-end`"
                 )
+            elif event_time_start >= datetime.now():
+                raise DbtRuntimeError(
+                    "Value for `--event-time-start` must be less than the current time if `--event-time-end` is not specififed"
+                )
 
         return func(*args, **kwargs)
 

tests/functional/cli/test_option_interaction_validations.py

@@ -1,4 +1,7 @@
+from datetime import datetime
+
 import pytest
+from freezegun import freeze_time
 
 from dbt.tests.util import run_dbt
 
@@ -28,3 +31,24 @@ def test_option_combo(self, project, event_time_start, event_time_end, expect_pa
                 "Value for `--event-time-end` must be less than `--event-time-end`" in e.__str__()
             )
             assert not expect_pass
+
+
+class TestEventTimeStartCurrent_time:
+    @pytest.mark.parametrize(
+        "event_time_start,current_time,expect_pass",
+        [
+            ("2024-10-01", "2024-10-02", True),
+            ("2024-10-02", "2024-10-01", False),
+        ],
+    )
+    def test_option_combo(self, project, event_time_start, current_time, expect_pass):
+        with freeze_time(datetime.fromisoformat(current_time)):
+            try:
+                run_dbt(["build", "--event-time-start", event_time_start])
+                assert expect_pass
+            except Exception as e:
+                assert (
+                    "Value for `--event-time-start` must be less than the current time if `--event-time-end` is not specififed"
+                    in e.__str__()
+                )
+                assert not expect_pass