May 21

Discover what makes May 21 special — holidays, historical events, and celebrations around the world.

星座

Gemini

生日花

Lily of the Valley & Hawthorn

诞生石

Emerald

Utility FYI Family

Part of the FYIPedia open-source developer tools ecosystem. Hub: ToolFYI

Site	Domain	Focus
UnitFYI	unitfyi.com	Unit conversion for 220 units across 20 categories
TimeFYI	timefyi.com	World clock, timezone converter, sunrise & sunset times
HolidayFYI	holidayfyi.com	Public holidays & observances for 200+ countries
NameFYI	namefyi.com	Name origins, romanization, and cultural naming traditions