a day of festival or public observance; a holiday (often a national or local festival day).
この町の一番大きな祭日は毎年夏に行われる。
The town's biggest festival day is held every summer.
祭日は神社で特別な行事があり、町がにぎやかになる。
On festival days, there are special events at the shrine and the town becomes lively.
今年の祭日は平日と重なったが、会社は特別に休みをくれた。
This year's festival day fell on a weekday, but the company gave us the day off.