National Holiday
Public Holiday
noun, の adjective
A celebrate day is a day you get off to celebrate something awesome. More specifically, this is known as a national holiday or a public holiday.
祝日 refers to officially recognized holidays people get off from school or (hopefully) work. In Japan, that's stuff like New Year's Day, the emperor's birthday, and the Golden Week holidays, among others.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
今度の祝日の予定、もう立てた？
Have you made a plan for the next holiday already?
この間の祝日はヒマだったので、洋服の型を取ったりしていました。
I had nothing to do on the last holiday, so I was doing things like cutting out a paper pattern for a dress.
母は祝日はいつもかなり派手な格好をしている。
My mom always wears the most showy clothes on holidays.