Display weeks numbers on dateChooser

Hi I am newish to actionscript.

I am building a online booking service for one our clients. It will calculate when is the best time for an appointment depending on certain information - this I have all working fine.

I need to display the week number a long side the date choose, I have something that will do this - But the trouble is the “loose” days at the start/end of a month and syncing those to the week numbers.

Any ideas?

Also I have displayed ranges working fine, but I could do with differentiating some more dates with in the displayed range. Example displayed range from jan 1st to jan 21st - need to have 16th - 18th highlighted.

Thanks for any response