Return WeekNo (ISO 8601 standard)

In MS SQL, January 1 of any year defines the starting number for the week. The DATEPART(wk, 'Jan 1, xxxx') always return 1. However, a lot of reports Week No is actually based on ISO 8601 standard, that is January 1 of any year can be Week 53/52 or Week 1. (http://www.merlyn.demon.co.uk/weekinfo.htm#IDC)The Rule is as […]