Circle of Darkness: Arena Resets happen every 6th week, giving a reset a full 42 days. There are now nothing different with reset days, starting with Round 37. A round always ends at the stroke of midnight at Eastern Datetime Saving Time, on Saturdays going onto Sundays. This is an attempt to at least give some fairness to everybody in the world, as at least you'll have Sunday to rest up.. in theory. Circle of Darkness: Arena Tourney Resets on 1st, 11th, and 21nd. On the 1st, it will reset on the stroke of midnight going from last month to the 1st on EDT time. On the 11th, it will reset at 8 AM EDT, and 4PM EDT on the 21st.