This RT extension provides a calendar view for your tickets and your
reminders so you see when is your next due ticket. You can find it in
the menu Search->Calendar.

There's a portlet to put on your home page (see Prefs/MyRT.html)

You can also enable ics (ICal) feeds for your default calendar and all
your private searches in Prefs/Calendar.html. Authentication is magic
number based so that you can give those feeds to other people.