Question is in the title
I'm not a current player but it used to be that way I always think it is on Wednesdays or weekends
No more…
After you have completed many tasks or only on the weekend
This season I don't think there are any more, or only 100+
You will only get an Ep Boost if you do not complete the stamp card. If you do not complete the stamp card you will receive a percentage ep boost the next day (4:00 p.m.). But it brings you more to do the stamp card instead of waiting for the ep boost
Fill up the stamps a day, and then play no Fortnite for a day and BAM you have EP boost.