A court release said Wednesday that sentencing for 28-year-old Mehserle, originally set for Aug. 6, had been moved to Nov. 5.
Last week a jury found Mehserle guilty of involuntary manslaughter instead of second-degree murder for fatally shooting Grant at the Fruitvale BART station last year.
Mehserle faces up to 14 years in prison.
Mehserle's conviction sparked a wave of protests that resulted in damage to about 30 businesses and the arrests of dozens of people, but a group is now planning a support rally for Mehserle, set for Monday in Walnut Creek.
A Facebook page about the event says the rally is not about inciting violence, hatred or rioting and that anyone who plans to do those things should stay home.
The rally is scheduled for 2 p.m. Monday at the Walnut Creek courthouse.
The Associated Press contributed to this report