The 501M circular shuttle service operates clockwise from approximately 5:45 am to 1:45 am every day. There is no overnight service on this shuttle route.
The scheduled times for the 501M buses are available for specific stops on the TTC.ca site.
For instance:
The stop at Queensway and Windermere is http://www.ttc.ca/Schedule/schedule.jsp?Route=501W&Stop=e.b._on_The_Queensway_at_Windermere_Ave.
And the stop on Marine Parade (east leg) at Lake Shore Blvd is http://www.ttc.ca/Schedule/schedule.jsp?Route=501E&Stop=s.b._on_Marine_Parade_Dr_%28East%29_at_Lake_Shore_Blvd_West.
TTC Customer Communications is revising the 501 Queen map on the TTC.ca site to better show the 501M service information.