"Han" means half, as in half past the hour. Unlike English, "gozen (a.m.)" and "gogo (p.m.)" come before the time. For minutes, "fun" or "pun" is used depending on the number..
one o'clock ichi-ji 一時
two o'clock ni-ji 二時
three o'clock san-ji 三時
four o'clock yo-ji 四時
five o'clock go-ji 五時
six o'clock roku-ji 六時
seven o'clock shichi-ji 七時
eight o'clock hachi-ji 八時
nine o'clock ku-ji 九時
ten o'clock juu-ji 十時
eleven o'clock juuichi-ji 十一時
twelve o'clock juuni-ji 十二時
Useful Expressions:-
time jikan 時間
minutes fun/pun 分
a.m. gozen 午前
p.m. gogo 午後
noon shougo 正午
What time is it? Nan-ji desu ka. 何時ですか。
It's one o'clock. Ichi-ji desu. 一時です。
It's 9 a.m. Gozen ku-ji desu. 午前九時です。
It's 3:30 p.m. Gogo san-ji han desu. 午後三時半です。