Fix DateTimeError for non-valid timezones

CHANGES.rst

@@ -4,6 +4,7 @@ Changelog
 2.5.0 (unreleased)
 ------------------
 
+- #2395 Fix DateTimeError for non-valid/old timezones
 - #2396 Add after sequential transition event handler
 - #2394 Ajax support for transitions retract and retest
 - #2393 Allow empty analysis method selection

src/senaite/core/api/dtime.py

@@ -33,6 +33,7 @@
 from bika.lims.api import get_tool
 from DateTime import DateTime
 from DateTime.DateTime import DateError
+from DateTime.DateTime import DateTimeError
 from DateTime.DateTime import SyntaxError
 from DateTime.DateTime import TimeError
 from zope.i18n import translate
@@ -139,7 +140,11 @@ def to_DT(dt):
         except (SyntaxError, IndexError):
             return None
     elif is_dt(dt):
-        return DateTime(dt.isoformat())
+        try:
+            # XXX Why do this instead of DateTime(dt)?
+            return DateTime(dt.isoformat())
+        except DateTimeError:
+            return DateTime(dt)
     elif is_d(dt):
         dt = datetime(dt.year, dt.month, dt.day)
         return DateTime(dt.isoformat())

src/senaite/core/tests/doctests/API_datetime.rst

@@ -184,6 +184,19 @@ Timezone aware datetimes are converterd to `GMT+<tzoffset>`
     >>> dtime.to_DT(local_dt)
     DateTime('2021/08/01 12:00:00 GMT+2')
 
+Old dates with obsolete timezones (e.g. LMT) are converted as well
+
+    >>> old_dt = datetime(1682, 8, 16, 2, 44, 52)
+    >>> old_dt = dtime.to_zone(old_dt, "Pacific/Port_Moresby")
+    >>> old_dt
+    datetime.datetime(1682, 8, 16, 2, 44, 52, tzinfo=<DstTzInfo 'Pacific/Port_Moresby' LMT+9:49:00 STD>)
+    >>> old_dt.utcoffset().total_seconds()
+    35340.0
+    >>> old_DT = dtime.to_DT(old_dt)
+    >>> old_DT
+    DateTime('1682/08/16 02:44:52 Pacific/Port_Moresby')
+    >>> old_DT.tzoffset()
+    35340
 
 Convert to datetime
 ...................
@@ -247,6 +260,12 @@ Get the timezone from `datetime.date` objects:
     >>> dtime.get_timezone(dt.date)
     'Etc/GMT'
 
+We can even get the obsolete timezone that was applying to an old date:
+
+    >>> old_dt = datetime(1682, 8, 16, 2, 44, 54)
+    >>> old_dt = dtime.to_zone(old_dt, "Pacific/Port_Moresby")
+    >>> dtime.get_timezone(old_dt)
+    'LMT'
 
 Get the timezone info
 .....................
@@ -337,6 +356,9 @@ Check if timezone is valid
     >>> dtime.is_valid_timezone("CEST")
     False
 
+    >>> dtime.is_valid_timezone("LMT")
+    False
+
 
 Get the default timezone from the system
 ........................................