Slap Day, called स्लैप डे in Hindi, falls on February 15, the day right after Valentine's Day, marking the start of what's popularly called "Anti-Valentine Week" — a playful, informal counterpart to the romantic Valentine's Week that precedes it. It has no formal historical origin; it grew organically through pop culture, greeting cards, and social media, particularly among young people in India.

In keeping with its cheeky theme, Slap Day is treated as a light-hearted day for jokingly "settling scores" with an ex or venting about a frustrating situation, expressed almost entirely through humor — memes, jokes, and playful Slap Day Shayari shared among friends rather than any literal action.

It's most visible in India and other South Asian countries, where the full Valentine's Week and Anti-Valentine Week format has become a widely recognized, if informal, social-media tradition. People also swap a witty Slap Day Status update to join in on the fun.