For instance: if, since the last back up or export, I made 25 new appointments in Calendar (1) Appointments (red) and then discover Calender (2) Special Occasions has become corrupted or events and many "repeat" reminders inadvertently deleted, then I OBVIOUSLY do NOT want to restore the entire Profile and/or all Calendars because that would revert me to a very obsolete (superceded) Appointment Calendar.  By restoring the Special Occasions calendar (and all others) I would have to over write all other Calendars  such as the Appointment Calendar and I have no way of remembering which new events I made in the Appointment Calendar.  So, fixing one problem (restoring Special Occasions calendar) creates a far worse problem by reverting me to a prior Appointment calendar that has been superceded.  This dilemma seems obvious enough in real life that any designer should anticipate it.  

I find instructions on how to Export a calendar but nothing on how to Import one but I am not even sure if an import would be the correct solution to the problem at hand. Here is the problem: Example: I have three Calendars (1) Appointments (red), (2) Special occasions (Blue) and (3) Favorite Quotes. This is what Mozilla invites us to do! So their designers should anticipate obvious problems. Each week Windows 7 does an automatic back up of all my data. Also each week I export each calendar to a back up directory I created. Each is saved individually as an .ics file. (iCalander). (See attached screen shot.. but.... I now notice this system does not allow me to attach a screen shot so as to effectively facilitate communication... maddening ... so just presume each calendar is separately exported to a separate file that I can identify.) Presume that, since the last back up and/or export that Calender (2) Special occasions (Blue) has either become corrupted or an office worker has inadvertently deleted many “repeat” reminders ) weekly, yearly, or monthly (etc)) Also imagine (as is likely) that I have made many changes to the Appointment calendar and do NOT want to disturb or over write this changes. I want to restore just that Special Occasions calendar - either from my Windows 7 back up or from the directory to which I have Exported them as a secondary back up. I know and am informed here that Thunderbird stores the Calendars in the Profile but there is no way of telling which or what is Calender 1 or 2 or 3 since Thunderbird does not even use my file names (Appointments, Special Occasions, etc.) rather crazy and totally counter-intuitive. I am also told the Calendars are not stored separately in the Profile (I think that design is dumber than stupid) but are part of a larger database that can not be severed out so we may replace the entire Profile and all calendars or nothing. That is we can only restore/replace all Calendars or none. A totally absurd situation. I have not dared to try that for reasons that should be obvious — it would be an EVEN WORSE DISASTER since it would replace (over write) all other calendars that have been changed since the last back up and I do not want to destroy changes in one calendar just to restore a different calendar. For instance: if, since the last back up or export, I made 25 new appointments in Calendar (1) Appointments (red) and then discover Calender (2) Special Occasions has become corrupted or events and many "repeat" reminders inadvertently deleted, then I OBVIOUSLY do NOT want to restore the entire Profile and/or all Calendars because that would revert me to a very obsolete (superceded) Appointment Calendar. By restoring the Special Occasions calendar (and all others) I would have to over write all other Calendars such as the Appointment Calendar and I have no way of remembering which new events I made in the Appointment Calendar. So, fixing one problem (restoring Special Occasions calendar) creates a far worse problem by reverting me to a prior Appointment calendar that has been superceded. This dilemma seems obvious enough in real life that any designer should anticipate it. Who designs this stuff? What were they thinking? Were they thinking in real life events at all? It is VERY likely that a user would want to restore one calender without disturbing the others. First, if you *know* how to restore one (of several) calendars from a Windows back up and HAVE ACTUALLY DONE it do let me know. Please, no theories, actually proven and vetted solutions only. Only tell me when you have confirmed, in real life, that your solution works. Vet any answer. Second, otherwise please recall that, in fact, and contrary to what some people have written here, the separate Calendars *can be and are* separated out into individual files in an export directory. (See attached screen shot.) So there, in fact, are separate .ics Calendar files clearly identified in my export directory. Why on earth can't Thunderbird store them this way in the profile in the first place? Too much common sense to ask for? So now the question is: presuming that the exported .ics file is complete or not corrupted, can I simply *import* that exported .ics calendar file back into Thunderbird without disturbing my other calendars? This, of course, is what any reasonable user would want to do if they had a problem with just one of several very different calendars. It seems to me common sense that any end-user with several different calenders for different purposes might commonly be in a situation where they want to replace/restore just one calendar without causing havoc with regards to other calendars. Imagine that you have all Word documents in one document directory and one document is lost or corrupted. Naturally you want to restore just that one document from a backup and the LAST thing you will want to do is replace/restore all documents that may have been changed. Common sense. Obviously, if I knew this horrid design flaw existed I never would have installed Thunderbird in the first place. Common sense and every day experience should tell any software designer that, if we have several calenders (as Mozilla invites us to have) and one of them needs to be replaced or restored then we need to do that without restoring them all and making one problem far worse. We need to do this simply and easily and without making a career out of it. Again, please, I commonly see here, “Have you tried this? Have you tried that? Perhaps this? Refer to this 5 page haystack of needles” etc. These are not answers. If I can not do this simply and easily (without making a career out of it) then I really need to dump Thunderbird and get the heck out of such an absurd environment. Thunderbird! Get out of our way. We have work to do.