Problem with top bar date

[Jeffrey Needle <jeff needle gmail com>]

Hi.  A quick question.  For usability reasons, I use an older version of 
Thunderbird.  Using menulibre, I was easily able to create a menu entry 
for Tbird.  But when I try to set the default calendar under Options, 
Default Applications, Gnome doesn't display Tbird.  I love clicking on 
the date on the top bar and seeing upcoming events.  But nothing appears 
there, presumably because it's looking to the Evolution calendar, which 
is the default, but doesn't exist in my system.  Yikes!  How can I fix 
this?  Thanks.