Support events in UTC

Events in UTC need to have TAG rem2ics_utc.

Thanks to Dianne for the proposal and discussion.

README.rst

@@ -67,6 +67,16 @@ Format of the Remind MSG body
 
 The ``%"`` is omitted, if there is no description in the iCalendar.
 
+Support events in UTC
+---------------------
+
+Remind always uses the local timezone.
+Use something like this to export events in UTC:
+
+::
+
+  REM Tue AT [9:00 + $MinsFromUTC] TAG rem2ics_utc MSG Event
+
 Known limitations
 -----------------
 

remind.py

@@ -131,6 +131,11 @@ def _parse_remind(self, filename: str, lines: str = "") -> dict[str, dict[str, A
                     dtstart: datetime | date = datetime.strptime(entry["eventstart"], "%Y-%m-%dT%H:%M").replace(
                         tzinfo=self._localtz
                     )
+                    if "rem2ics_utc" in entry["tags"]:
+                        utcoffset = datetime(
+                            self._startdate.year, self._startdate.month, self._startdate.day, tzinfo=self._localtz
+                        ).utcoffset()
+                        dtstart = (dtstart - utcoffset).replace(tzinfo=ZoneInfo("UTC"))  # type: ignore
                 else:
                     dtstart = datetime.strptime(entry["date"], "%Y-%m-%d").date()