Every day there is a rotation of maps getting a bonus like 1.5 drop rate or 0.5 energy cost.
During the day (server time) the next bonus starts right after the first one runs out, but during the night there is a 4 hour gap. Bonuses stop at 23:00 server time and don't start until 03:00 server time. I'm playing from Europe and for me that is 09:00 - 13:00 and it includes my lunch break, so I'm regularly using up some energy just before the bonus starts again. That's a little frustrating. The Wonder maps have given me good XP, but when I want to collect cards for strengthening, getting 9 cards per run would be better.
Does anybody know why this is? I can't think of any technical or gameplay reason, but there must be one.