Week numbers are still available in the original datepicker -  http://keith-wood.name/datepick.html.

Feature to show week numbers

Here's that feature.

Use it like this: $("#datepicker").datepicker({showWeekNumbers: true, firstDay:1});

ISO week numbers starts on mondays, so this feature should not be used with firstDay=0.

Also apply the week number fix: http://dev.jqueryui.com/ticket/4285

I've done this and it's great. One issue is when you get to January 2010 it says week one is week 53 of the previous year.

Can this be fixed at all?

This is correct as it stands. The  ISO 8601 standard defines the first week of the year as "the week with the year's first Thursday in it". Hence week 1 of 2010 starts on Jan 4 and contains Thursday Jan 7. Jan 1 to 3 are relegated to the last week of the previous year.

hi, when is this patch gonna be included in the datapicker-stable?

Fixed in r3004, including localisation of the column header. Added a demonstration of the datepicker showing week of the year.