CalWeek class

The calweek module provide the class CalWeek. Instances represent specific weeks spanning 7 days Sunday to Saturday except weeks at the year beginning/end may be shorter. There are 53 or 54 numbered weeks in a year. Week 1 is always starts on January 1 of the year.

This is a traditional week number system different from the ISO 8601 standard. ISO 8601 week numbering is now more predominate, but still sometimes software needs to work with the old system.

For ISO 8601 week support in Python, use the isoweek module on which this code was based.

The CalWeek instances are light weight and immutable with an interface similar to the datetime.date objects. Example code:

from calweek import CalWeek
w = CalWeek(2011, 20)
print "Week %s starts on %s" % (w, w.day(0))

print "Current week number is", CalWeek.thisweek().week
print "Next week is", CalWeek.thisweek() + 1

weeknum() function

The calweek module also includes a weeknum() function compatible with Microsoft Excel's WEEKNUM formula function.