Crontab: How to interprent entry with shortformat day in the day of month field ?

[Gaute Hope]

Greetings,

Im the maintainer of gnome-schedule (http://gnome-schedule.sf.net) and
have the thrilling task of making a crontab editor (parser, editor) in
python. Now this works fairly well by now and gnome-schedule is
included in most of the big distribution (older versions, but
anyway..).

Then the question, I just discovered that I can write in an entry like
this:
> * * tue jan * ls

in my crontab, but not:
> * * tue jan tue ls

and (the only logical) works:

> * * * jan tue ls

i normally just replace text entries with their respective numbers as
i parse, and if a task that has been created manually is edited in
gnome-schedule and re-saved a completely new line with numbers is
used, but how am i supposed the first example? The only possible way I
can think of it is by parsing it the same way as the last one. Anyone
have some hints here? Or is this a crontab bug?

I am using vixie-cron.

- gaute