This Saturday as opposed to Monday, per The Boston Globe.
This will certainly ease the coming weekend of hell brought about by several Red Sox games, college move-ins and Labor Day tourist traffic.
Trains will be able to run faster, and the handicapped-accessible Breda trolleys should theoretically be able to traverse the line at full speed without derailing now that the track renovations are complete. The T expects the latter to enter service on the D Line by the end of the year.