VTODO's Last-Modified without 'Z'

[tieugene]

According to RFC-5545

The property value MUST be specified in the UTC time format

(e.g. LAST-MODIFIED:20210326T212333Z)
Storing datetime.datetime.utcnow() produces localtime format (w/o 'Z').
Using datetime.datetime.now(datetime.timezone.utc) produces error:

  File "/usr/local/lib/python3.9/site-packages/vobject/base.py", line 226, in transformFromNative
    raise NativeError(msg, lineNumber)
vobject.base.NativeError: At line 18: In transformFromNative, unhandled exception on line 18 <class 'vobject.base.VObjectError'>: 'Unable to guess TZID for tzinfo UTC'

Maybe this is linked with another bureport #154

PS. macOS 15.7 'Catalina', vobject 0.9.6.1 from brew

[grantm]

Not sure if it applies to your situation, but I found that the vobject library does not seem able to work with instances of datetime that use datetime.timezone.utc.

If you have Python 3.9 or later, you can use zoneinfo.ZoneInfo("UTC") instead. This also works if you install backports.zoneinfo on older versions of Python. Alternatively you can use pytz.utc instead.

In my case the datetime objects were being created by my psycopg2 database layer so I had to adapt them for use with vobject by doing this:

utc = zoneinfo.ZoneInfo("UTC")
vtodo.add("last-modified").value = todo.updated_at.astimezone(utc)