replace utcnow (#231)

CHANGES.rst

@@ -16,6 +16,8 @@ Other
 
 - Add mrsptcorr ref_file to core.schema [#228]
 
+- Replace uses of ``utcnow`` (deprecated in python 3.12) [#231] 
+
 - Updated JWST MIRI imager photom model to include time-dependent correction
   coeffs. [#235]
 

src/stdatamodels/util.py

@@ -227,9 +227,10 @@ def create_history_entry(description, software=None):
     elif software is not None:
         software = Software(software)
 
+    dt = datetime.datetime.now(datetime.timezone.utc).replace(tzinfo=None)
     entry = HistoryEntry({
         'description': description,
-        'time': datetime.datetime.utcnow()
+        'time': dt
     })
 
     if software is not None:

tests/test_util.py

@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 
 import pytest
 
@@ -259,7 +259,8 @@ def test_create_history_entry():
     assert isinstance(entry, HistoryEntry)
     assert entry["description"] == "Once upon a time..."
     assert entry.get("software") is None
-    assert (datetime.utcnow() - entry["time"]) < timedelta(seconds=10)
+    dt = datetime.now(timezone.utc).replace(tzinfo=None)
+    assert (dt - entry["time"]) < timedelta(seconds=10)
 
     software = {"name": "PolarBearSoft", "version": "1.2.3"}
     entry = util.create_history_entry("There was a tie-dyed polar bear...", software)