Custom Calendar Support and Future Events

Current date and time features list only "Day X, 9:02am", etc. Works great for tracking durations, etc, but...

I'd like the ability to:
put in a custom Calendar, including Months, # days per month, days of the week, # of months/days per year, and the current year
then be able to start a campaign or session at a specific date on that calendar,
as hours turn into days, and days into months and years, the calendar advances appropriately
Fantasy gaming happens "Early in the month of Lamashan, when cold winds blow", not "Day 47".

Future Events:
Once a calendar is implemented, it'd be nice to be able to set future reminders, such as:
-"Toilday, Rova 6 is the High Holiday for Abadar" or something like that, or
-2 days from now, at 8am, Lilly will feel the effects of filth fever

Of course, some of the Future Event functionality can be mimicked with effects, especially if one is willing to use a token to handle them. But since effects don't alert when they expire, it is easy to miss longer-term reminders. So, maybe a fast and dirty way to handle Future Event tracking is to implement pop-ups on effect expiration, with either a system option, or an effect-level option to suppress/activate.