Daily Treasures reset on the first day of each month. If you miss logging into the game and don't collect your daily treasure, when you log back in you then collect the next treasure you were up to last. That is, you don't skip daily treasures in the month's progression.
|5||150||2||20||200||1 Mystery Box||1|
|30||250||5||8||300||1 Mystery Box||1|
|40||350||2||11||400||1 Mystery Box||3 Spell Books|