In an initiative to show solidarity with menstruating women, a bar in Israel has decided to give them a 25% discount on drinks.
The two women behind the idea in Jaffa say the "bloody hour" is a recognition that women on their period deserve "a favour".
They hope the subject of menstruation will be more openly discussed, including by men.
The discount will be given on the basis of trust.
The owners of the Anna Loulou bar said that since women menstruated 25% of their lives, they deserved the discount at least for one night.
"The whole idea is to give a discount, attention and a treat to someone, to say 'we recognize you, we're aware of the special situation you're in right now, and hey, we want to do you a favour'," Moran Barir told the Israeli newspaper Haaretz.
Ms Barir explained that the idea began at the bar itself when once she ordered wine and the bartender did not remember whether she was asking for red or white.
"I told him simply 'Here's how you'll remember: I'm on my period, so bring me red'."
The discount will apply on Mondays, Tuesdays, Wednesdays and Saturdays.