Pegasus can only be done non-financially on Thursday, the day that that dungeon opens. Even then, you will still be limited to the number of entrance from the quest if you never saved up for those. On every other days except Thursday, you will need a star admission sign ticket, which you need to buy with IM. Other "normal" F7 can be done on any days.
Things to note:
Pegasus day, does not align with the weekend bonus exp
Pegasus is indeed faster since it lasts 40 rounds
Pegasus gives less exp since it only lasts 40 rounds and not 50
Rounds 40-50 in f7 give a huge amount of exp
Lvl cap is much more flexible in Pegasus , lvl 50-85.
Edited by Agitodesu, 28 January 2016 - 08:42 AM.