add logging to exception catch

superset/tasks/cron_util.py

@@ -18,11 +18,14 @@
 from datetime import datetime, timedelta, timezone as dt_timezone
 from typing import Iterator
 
+import logging
 from croniter import croniter
 from pytz import timezone as pytz_timezone, UnknownTimeZoneError
 
 from superset import app
 
+logger = logging.getLogger(__name__)
+
 
 def cron_schedule_window(cron: str, timezone: str) -> Iterator[datetime]:
     window_size = app.config["ALERT_REPORTS_CRON_WINDOW_SIZE"]
@@ -33,6 +36,8 @@ def cron_schedule_window(cron: str, timezone: str) -> Iterator[datetime]:
     except UnknownTimeZoneError:
         # fallback to default timezone
         tz = pytz_timezone("UTC")
+        logger.warning(
+            "Timezone %s was invalid. Falling back to 'UTC'", timezone)
     utc = pytz_timezone("UTC")
     # convert the current time to the user's local time for comparison
     time_now = time_now.astimezone(tz)