I have a mind boggling datetime problem I'd like some help with. Here's the scenario:

Given the week number of the current week of the year (calculated as (DateTime.Now.DayOfYear / 7) + 1) I need to obtain a range of week numbers that fall between:

- LastMonth i.e from the first to the last day of last month.
- LastQuarter i.e from the first day to the last day of the of the last quarter (6 months ago to 3 months ago).
- ThisMonth i.e from the first to the last day of this month.
- ThisQuarter i.e from the first day to the last day of the of this quarter (3 months ago to now).

Any pointers will be greatly appreciated.

Thanks.

Keith.