should be at least two time zone (3:00/15:00 or even 21:00 if there is enough players (15+))
only fair to those who cant make it during 15:00 since its monthly?
not like having 3 in a month but one month with 15:00 and the month after with 3:00 etc
well if the event only have a few joined, it should just call it off or just for the map reward only