Does anyone know of a method or calc to work out the ISO week number from a time stamp field?
ISO 8601 week numbers determines week 1 of the year as being the one with the 1st Thursday. So for example 1st January 2006 was using the ISO standard week 52 of 2005.
The months are determined by the week periods. 4,4,5. i.e. January has weeks 1-4, February has weeks 5-8, March has weeks 9-13, April has weeks 14-17, etc.