歳旦
さ
い
た
ん
Meanings
1
Specifically the morning of New Year's Day. Often used in formal or literary contexts. Compare 元旦 (がんたん), which is more common.
See also: 元旦
I like the refreshing air of New Year's morning.
2
Refers to the entire day of January 1st. Less common than 元旦 or 元日 in everyday speech.
On New Year's Day, the family gets together.