Sorting GtkListStore date column

[Guy Rouillier <guyr-ml1 burntmail com>]

I'm fairly new to GTK programming, and I'm helping out on an open source 
GTK-based project (gcvs, part of the cvsgui project.)  We have a 
GtkListStore with a column containing date.  The column is specified as 
G_TYPE_STRING.  When sorted, it does an alphanumeric sort, so in English 
it puts all the Fridays together first, followed by all the Mondays, 
Saturdays, Sundays, etc.

Obviously, I want to sort this in date sequence.  How do I accomplish 
this?  I searched the archives before posting and couldn't find anything 
applicable.  Thanks.

--
Guy Rouillier