Directed by John Dapolito, the production was originally scheduled to continue through Jan. 6, 2013. Performances will now conclude Dec. 30.
The cast features Adam Mucci, Katie Webber, Brandi Nicole Wilson, James Wirt, Roxie Lucas and Kevin O'Donnell.
"A family, a will, a gun, a marriage, an affair, a wheelchair and a murder attempt… just your normal Christmas holiday!," press notes state. "Let's Kill Grandma This Christmas is a rip-roaring holiday black comedy that takes place as a family gathers to celebrate Christmas Eve dinner. After a rough year rife with economic difficulties, some family members ponder the question...at 80 years old, how much longer does Grandma need to hold on to her vast fortune?"
Sets and lights are designed by Harry Feiner with costumes by Philip Heckman, sound by Ben Selke and props by Jeena Yoon. Casting is by Judy Bowman.
Show times are Monday at 7 PM, Wednesday-Friday at 8 PM, Saturday at 2 PM and 8 PM and Sunday at 3 PM and 7:30 PM. Theatre at St. Clement's is located at 423 West 46th Street. Tickets are $69 and can be purchased by clicking here.