Comment 7 for bug 849624

I tried several ways now, but I think there's only one workaround without modifying Thunderbird...

Whenever TB is configured to download mails upon startup, it selects the Inbox folder of the default account. This occurs AFTER Lightning is loaded, so Lighting is unable to bring the calendar up.

One workaround would be to use an internal URL (i.e. 'about:calendar'), because TB does not select the folder view, when it is started with a URL; it displays this URL instead!

I got this working, even with the desired view ('about:calendar-month' etc.) - but I'm not sure, whether this is the right way to go...
Wouldn't it be better to completely handle this URL instead, although it does not really make sense in Thunderbird?!

What do you all think about that?