While it's hard to find precise hints, it can be surmised from certain lines that the entirety of Shakespeare's Twelfth Night takes place over the course of three months. In act 5, scene 1, Antonio tells Orsino that he and Sebastian have spent the past three months together and have never left each other's side, day or night. Since it can be surmised that the two met when Antonio saved Sebastian from the shipwreck, we can assume that the play takes place over a three-month period.

It is, however, difficult to place where in the story such a lengthy time lapse occurs. Many of the acts and scenes occur in rapid succession with very little time passing between them. On the off chance that Antonio and Sebastian were close before the shipwreck occurred, the action of the play would take closer to a week to occur.

In Shakespeare’s Twelfth Night, one day has elapsed from the first scene in the play to Act II; scene iii.  In Act II; Scene iii it is late at night and Sir Toby and Sir Andrew are drinking in Olivia’s house.  Maria and the two men plot against Malvolio.  Act II; scene iv marks the beginning of a new day.  In the new day, Maria plays her prank on Malvolio.  There are no more clear markers of time after Act II, so it seems that everything that follows all the way up to the resolution in Act V all takes place on the same day.  Therefore, all of the action in Twelfth Night takes place in two days and one night.