Things get weird if you use weeks as a unit and then also display the year. For example, if you have an event that took place on 2010-01-01, then iso_week_of(20

Things get weird if you use weeks as a unit and then also display the year. For example, if you have an event that took place on 2010-01-01, then iso_week_of(2010-01-01) will return 53 and year_of(2010-01-01) will return 2010. So your wonderful app might display "Week 53, 2010", which makes it look like it's the end of 2010.