A new WeekNumberBase property has been added to the Calendar since build 2007.2.51. The property can be set to "None", "Month" or "Year". If it is set to "Month", the Calendar/DatePicker would display a week number in front of every week based on the month, meaning the first week of the month has a week number of "1", the second week of the month has a week number of "2", and so on. If it is set to "Year", the Calendar/DatePicker would display a week number in front of every week based on year, meaning the first week of the year has a week number of "1", the second week of the year has a week number of "2", and so on. The default value is "None", meaning no week number is displayed.

The appearance of the week numbers (font, color, background, etc) can be customized through WeekSelectorStyle. The appearance of the week number header can be customized through MonthSelectorStyle.

A new sample has been added to demonstrate this feature. To view the sample, please load the demo project, then go to Calendar -> Features -> Week Number.