The time you have for a turn depends on the format of the game you choose.
In causal you get 23 hours to start your turn, after you start the turn you get 1 hour to finish.
speed games you get 5 minutes to start and finish your turn.
I did a couple fiftynine plus minute turns in a game once.
since this has been moved to Q&A: You actually have 24 hours to take your turn in a normal game with 1 hour to complete it once you start, whichever comes first.
for owenshooter's subplot of humorous reparte'. . . actually it's never 'whichever' it's always her... because I'm just that good.