It's time for class to begin.

该是上课的时候了。

Hurry up, it's time for class.

赶快，到了上课的时候了。

Hurry up it's time for class.

赶快，到了上课的时分了。

It's time for class, hurry up!

上课时间到了，快点！

Time is up. It's time for class.

时间到了，该下课了。