ladies' night

ladies' night (plural ladies' nights)

1. A night in which women are given free admission into a venue.
   • 2004, Amy Winehouse, Salaam Remi, “Fuck Me Pumps”, in Frank, performed by Amy Winehouse:

     You can't sit down right, 'cause your jeans are too tight / And you lucky it's ladies' night

Also called "ladies' day" if held during daytime.

• girls' night out