To introduce the new hours, the MBTA will offer fare-free service on five Friday and Saturdays nights after 9 p.m., starting Sept. 5.

As part of a new schedule that takes effect Aug. 24, the T plans to extend evening service by almost an hour on all four subway lines on Friday and Saturday nights and on a handful of bus routes, including some on the Silver Line.

For the first five weekends after the change, commuters can ride for free on any train, ferry, or bus line. The MBTA says most buses and trains will run every 30 minutes during the extended hours. On the Red line, between Alewife and JFK/UMass, trains will run every 15 minutes.