if they made the dungeons time-based, static parties at a scheduled time would largely be used, and because i cant base my schedule around a game i shouldnt be able to take part in the dungeons?

i want to be able to get on when its convenient for me, get a party (pick up or not, i dont care) and have fun. i dont want to have to have a static party that relies on me getting on at 7 pm on tuesdays, thursdays and saturdays.