When I start TB it takes a very long time for my several calendars to be populated. I have to wait for several minutes before I can see my events for today and the rest of the week/month. This is very annoying when I am in a hurry to know if I should be doing something asap. A work around this problem would be to start with populating all the calendars for this and next month first. Chances are that users will not be in a hurry to find out about events in the past, and they will probably not even realise it takes so long for the process to be completed.