datebook.xml

Hi!

I'm trying to write a python script to parse the opie calendar file
(datebook.xml) which is an xml file in order to convert it to ical format.
The field names used are pretty self explanatory, however when it came to
repeated events i got stuck. The file syntax codes the weekdays on which an
event is repeated in form of a number.
My problem now is i find myself totally unable to find any relation between
the combination of weekdays and the number in datebook.xml.
By trying out random weekday combinations i got the following:

TUE+wed 6
TUE+wed+thu 14
mon+TUE+wed+thu 15
TUE+thu+fri+sat+sun 122
TUE+thu+fri+sat 58
TUE+thu+fri+sun 90

mon+TUE 1
mon+WED 5
mon+THU 9
mon+FRI 10

the weekday written in capital letters is the weekday on which the original
instance of the event occurs.

Any help would be highly appreciated!

-- 
Rami El Shafie