As of June 1st, 2018, you're allowed to park on unsigned streets for 6 hours on weekends and statutory holidays from 7am to 7pm. This effectively doubles the amount of time you can park in one spot during these time-frames.
This change is only for streets that do not have any posted signs. For all other streets, regular signage rules apply. If there is no signage to indicate what the parking limits are, a 3-hour parking limit is in effect Mon-Fri 7am - 7pm.