One O'clock
noun
When it's one o'clock it's one o'clock. It's time to eat lunch, or take a nap, or something.
いちじ
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.
毎日一時にランチを食べます。
I eat lunch at one o'clock every day.
一時までにおもちゃをかたづけなさい。
Put your toys away by one o'clock.
もし私のところで働くなら、あなたのシフトは午後一時から遅くとも三時までになりますが、よろしいですか？
If you worked for me, your shift would start at one o’clock in the afternoon and end at three o’clock at latest. Sound good?