allow to edit files

my_modules/expiry.py

@@ -0,0 +1,32 @@
+from datetime import datetime, timedelta, timezone
+from typing import Optional
+import re
+
+PRESET_H = re.compile(r"^(\d+)h$")
+PRESET_D = re.compile(r"^(\d+)d$")
+
+def parse_expires(value: str | None) -> datetime | None:
+  """Parse expiration presets or ISO datetime."""
+  if not value or value == "never":
+    return None
+
+  value = value.strip()
+  if not value:
+    return None
+
+  if m := PRESET_H.match(value):
+    return datetime.now(timezone.utc) + timedelta(hours=int(m.group(1)))
+  if m := PRESET_D.match(value):
+    return datetime.now(timezone.utc) + timedelta(days=int(m.group(1)))
+  try:
+    return datetime.fromisoformat(value.replace("Z", "+00:00")).astimezone(timezone.utc)
+  except Exception:
+    return None
+
+def ensure_utc(dt:datetime):
+  """Ensure a timezone-aware UTC datetime or None."""
+  if dt is None:
+    return None
+  if dt.tzinfo is None:
+    return dt.replace(tzinfo=timezone.utc)
+  return dt.astimezone(timezone.utc)