The "Spend the Night with Billy Crystal" shows at Verizon Hall were originally scheduled for Monday, March 20 and Tuesday, March 21.
Tickets to the March 20 date will now be honored for Friday, April 14 and tickets to the Tuesday, March 21 date will be honored for Saturday, April 15.
On Twitter, Crystal apologized to his Philadelphia fans.
"Sorry to my fans in Philly for postponing my show dates. Fighting a nasty flu," Crystal tweeted.
Sorry to my fans in Philly for postponing my show dates.— Billy Crystal (@BillyCrystal) March 18, 2017
Fighting a nasty flu. New dates are April 14-15.
It was recently announced actress Bonnie Hunt will be joining Crystal as moderator and interviewer.
Tickets can be purchased at KimmelCenter.Org, the Kimmel Center box office, or charge by phone at 215-893-1999.