After the rout, Walton "kept his lodging until the evening of the morrow" [Chapter XIII].  He then gambled all night and was tempted by Glenleven the next morning.  At "noon on the morrow" [Chapter XIV] he wrote Lord Portland, then having "kept his lodgings for two days" he heard from Bentinck on Monday morning.  So he wrote on Saturday, was tempted on Friday, and the rout was Wednesday evening.