Linking calendars .


As you can create custom calendars, it would be a good idea to be able to link them. So we have the normal Earth Gregorian Calendar and a custom one - Eg: Vulcan Calendar. The idea is that you would designate where a date on one calendar equals a date on another calendar. That way you can create an event and it will appear on both systems. So First Contact is 5th April 2063, and be on whatever date the Vulcans use. The length of day would be something that may need to be considered. 24hr day vs 26 hr day. Eventually the day length difference, week and month differences will have a long term cumulative effect.
The useful of this would be when you talk about an event from a human point of view, you use one calendar, when you talk about it from a vulcan point of view, you use their calendar.