一日（いちにち）— one day; all day
一日 休み です。
I have the whole day off.
In detail
Words
一日ichinichione whole day
休みyasumitime off
ですdesu(polite sentence ending)
一日 read いちにち means one day or a whole day. Read ついたち, it means the first day of a month.
Coco-sensei
