According to Jeff, I’ve become a smelly Nokia contractor (the reason he stayed with Luis instead of at Mako’s place in Boston, although I’m sure he was referring to Rob Taylor causing the smell). Part of this entails exchanging project schedules with various managers, where time is often talked about in terms of numbered weeks of the year, like: Foo task will be completed by week 42 of 2005. We ran into some problems with varying definitions of these numbers when exchanging schedules with people running on different platforms. Then we realised that even the software we’re using seems to have different ideas about what’s going on too…

• Outlook and Evolution seem to agree, and define the week as starting on Monday, and the first day of the year is always week 1, even if this results in a truncated week. Hence, week 1 of 2006 starts and ends on Sunday 1st January, and then week 2 begins on Monday 2nd, etc. It’s my belief that this is the correct behaviour as defined by some ISO standard somewhere which governs week numbers.
• GtkCalendar gets the week number correct, in that the first day of the year is always in week 1, but varies its definition of the first day of the week depending on your locale. This is presumably so that the display of the weeks is correct, but using it to number the weeks results in bogus week numbers. For me in LOCALE=en_GB it claims that week 1 of 2006 starts on Sunday 1st January, and ends on Saturday 7th January, making my week numbers one lower than the rest of the world.
• Planner uses GtkCalendar for inputting dates, so gets it wrong there as described, but seems to get it wrong in its Gantt chart view in a different way. It has the week starting on Monday, but claims that January 1st 2006 is the last day of week 52 of 2005. This results in week numbers that, match those GtkCalendar give me on weekdays, but differ over weekends, and are still totally bogus when I try and talk about project plans with my managers.

The result is a whole world of pain, and at best causes extreme confusion when we provide documents referring to both dates and week numbers which are inconsistent with each other in their minds, and at worst makes our managers think we’ll have things done a week sooner than we do. I’m not using Evolution at the moment for calendaring stuff, so I can manage if I remember to add one to all my 2006 week numbers when interacting with managers based on GtkCalendar and Planner, but this all seems to be horribly broken. I really don’t want to have to do this for the whole year.