Waarom staan er gegevens voor "Week 53" in mijn statistieken? Er zijn toch maar 52 weken in het jaar?

There are a number of days either at the beginning or at the end of the year that are not part of the "normal" 52 weeks of the year. PHP and/or MYSQL treats weeks as being not just any 7-day period, but specific periods from Mondays to Sundays. This can leave some "stray" days if a year starts or ends in the middle of a week. For example, in 2005, the year started on a Saturday. PHP/MYSQL does not treat the two days of Saturday and Sunday as the first week of the year, rather "Week 53".