The Prime Minister will apparently visit the Governor General on Friday to ask that Parliament be prorogued and scheduled to return for a Throne Speech on October 16.
By the current calendar, that eliminates 20 sitting days, but then adds three. Presumably that leaves a legislative year of 108 days, which would match 2003 as the shortest non-election calendar since 1968.
See previously: Should you be upset that Stephen Harper is proroguing Parliament?