Take a look at TeamUp (www.teamup.com) for how they have calendars with sub-calendars.

Would be nice to have a tagging or sub-calendars function in the calendar for superior, fine tuned organization.

For instance, I can create a single/master calendar "Family" and then tags/sub-calendars "kid 1", "kid 2", "kid 3", "wife", etc.

Then events will be "family:kid 1", etc. and can be search isolated by tag/sub-calendar

When sharing the master calendar, it would include all events of its related tags or sub-calendars. This will simplify calendar sharing (instead of sharing 5 separate calendars, only have to share 1). But also, the sub-calendars would be able to be shared individually, containing only their own events.

This is useful for families, businesses, or any kind of group.