[zeeZ]

They unlock at 6 in central european time (5 in UK).

This is the only month of the year when I will consistently get out of bed at 5:55, give the puzzles up to 2.5 hours, then have breakfast and get ready for work.

Personally I find it super convenient since I and many of my close colleagues begin work so late, but I also know a lot of people who would be on their commute to work at that time.