What is the difference between on time and in time?

On time = Promptly; at the right time 準時
eg: Please be come on time for the oral examination.
請準時出席口試

In time = Early enough 及時
eg: The police arrive just in time to arrest the escaping robberies.
警員及時將在逃的劫匪拘捕

2006-11-11 23:05:57 補充：
(TYPING MISTAKE)Please come on time for the oral examination. ORPlease be on time for the oral examination.

TIME
n.
1. 時間;時[U]
How time flies!
光陰似箭。
2. (辦事所需)時間[U][S]
I have no time for novels.
我沒有閒暇讀小說。
3. 次,回[C]
How many times have you been to France?
你到法國去過幾次?
4. (經歷的)一段時光[C]
We had a hard time finding a ferry boat.
我們好不容易找到一隻渡船。
5. 歷史時期,時代[P1]
In ancient times infant mortality was extremely high.
在古代嬰兒死亡率極高。
6. 【體】比賽時限,暫停
7. 時機,時刻,時候[C][U][+to-v][+(that)]
Now is the time to fight back.
是反擊的時候了。
8. 【音】拍子,節拍[U]
9. 一生;死期;服役期;刑期[U]
10. 倍[C]
The earth is 49 times the size of the moon.
地球的大小是月球的四十九倍。
vt.
1. 安排...的時間;為...選擇時機[H][+to-v]
The plane is timed to arrive at 8 o'clock.
飛機定於八點抵達。
2. 測定...的時間;記錄...的時間[(+at)]
The swimmer was timed at 50.50 sec.
這名游泳者的成績被測定為五十點五零秒。
3. 安排...的速度;使合拍子
a.
1. 有關時間(方面)的
The earth is divided into 24 time zones.
地球被分為二十四個時區。
2. 定期的
3. 分期的
4. 定時爆炸的
The police defused a time bomb in the building.
警察在那幢大樓裡拆除了一枚定時炸彈。
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IN TIME
ph.
1. 及時;早晚;終將;慢慢地