Less than one day from the graveyard to the swordfight.

In the Second Quarto and First Folio editions, Claudius says to Laertes as they depart the graveyard: (5.1.186)

"Strengthen your patience in our last night's speech,/We'll put the matter to the present push./…/An hour of quiet shortly shall we see;/Till then in patience our proceeding be."

In the First Quarto edition: (Q1: 3496)

"This very day shall Hamlet drinke his last,/For presently we meane to send to him."