If you have a problem, you will get more useful information by explaining the problem. On your question, the built-in restore functions can do a full profile or an address book.

Yesterday, I was trying to backup Thunderbird. Done it many times but this time I somehow deleted the backed up profile!! I was able to start over and create my e-mail account and email was restored from server. However, calendar is blank. I have a copy of a profile from several months ago that has a calendar backed to that point in time. The calendar is important because has a number of years of data. If I can restore the calendar up to a point several months ago I can easily rebuild it up to current.

Tasks can be restored this way also but not critical.

Thanks for any help you can give me.