Fix date handling in feeds

Cf. comment in new zoned_datetime function.

Also fix a concert pubDate.

1 files changed, 15 insertions, 19 deletions

diff --git a/admin/feeds/build-feed.py b/admin/feeds/build-feed.py
index e010b63..6c95161 100755
--- a/admin/feeds/build-feed.py
+++ b/admin/feeds/build-feed.py
@@ -18,25 +18,21 @@ from helpers import (
 )
 
 
-# TODO: handle timezones correctly.
-# Places to disambiguate:
-#
-# - concerts.in:
-#   either add the zone explicitly, or deduce it from the place,
-#   assuming all times in concerts.in are local times.
-#
-# - concerts-pubdates.json:
-#   just add the zone explicitly.
-#
-# Until then, assume all these "naive times" describe the same timezone
-# (CET/CEST).
-
-
-TIMEZONE = datetime.now().astimezone().tzinfo
-NOW = datetime.now(tz=TIMEZONE)
-DATE_FORMAT = '%-d %b %Y %H:%M %z'
+def zoned_datetime(dt):
+    # Assume that whoever wrote the naive timestamp that this datetime
+    # was generated from had the same local time we do.
+
+    # Note: even if we assume that all timestamps in concerts.in and
+    # concerts-pubdates.json come from the same "zone" (Europe/Paris),
+    # the *time offset* can differ (CET vs CEST), so we can't just
+    # define a global TIMEZONE = datetime.now().tzinfo and slap that
+    # on every datetime.
+
+    return dt.replace(tzinfo=dt.astimezone().tzinfo)
 
-# TODO: add item pubDate
+
+NOW = zoned_datetime(datetime.now())
+DATE_FORMAT = '%-d %b %Y %H:%M %z'
 
 
 LOCALIZED_TEXT = {
@@ -132,7 +128,7 @@ def generate_concert(concert, concerts_url, pubdates, lang):
     pubdate_str = pubdates[concert.time.isoformat(timespec='minutes')]
 
     if pubdate_str is not None:
-        pubdate = datetime.fromisoformat(pubdate_str).replace(tzinfo=TIMEZONE)
+        pubdate = zoned_datetime(datetime.fromisoformat(pubdate_str))
         item.append(E.pubDate(pubdate.strftime(DATE_FORMAT)))
 
     return item