The railroad says nine extra trains will begin running from Penn Station Friday afternoon.
The Babylon and Port Jefferson branches will have three extra trains.
There will be two additional trains on the Port Washington branch and one on the Far Rockaway branch.
LIRR also will be replacing trains with buses on the Far Rockaway branch from 6:16 p.m. Saturday until 12:05 a.m. Monday. That's because they will doing some track work between Far Rockaway and Valley Stream.
More information available at mta.info/lirr.
Yom Kippur, the Day of Atonement, begins at sundown Friday.