Save 09 is 1/30 - The last day before Final Boss
Save 10 is 1/31 - right before the last boss, teleport to the highest floor
Save 11 is 3/3 - Post game for maxed social links conclusions
Save 13 is NG+ Save
I had no trouble fighting on maniac with my 3 maxed-out Personas, I heavily relied on attack, defense, and evasion sutras and lots of magic mirrors for survivability from my inventory.
Save 10 is 1/31 - right before the last boss, teleport to the highest floor
Save 11 is 3/3 - Post game for maxed social links conclusions
Save 13 is NG+ Save
I had no trouble fighting on maniac with my 3 maxed-out Personas, I heavily relied on attack, defense, and evasion sutras and lots of magic mirrors for survivability from my inventory.