An .ics file that tells you what date the location puzzle is released and when the actual puzzle day is?
You could even include the link as the location for the location puzzle and update the calendar a day in advanced with where the actual puzzle is.
Even just a Google Calendar would work that we could import.
This would obviously be separate for each city/location.
Puzzled Pint is always second Tue of the month with puzzle being release on Fri before that - I have added this to my own calendar (very easy). There are only very rare exceptions from this like these elections or maybe Christmas month.