'all the time' or 'at all time'?

[jin007]

Which one of these is corect English?

He is a good instructor. He is patient and helpful at all times.

He is a good instructor. He is patient and helpful all the time.


Thanks.

[mykwyner]

They are both correct. The first one at all times implies that he is helpful and patient whenever he needs to be. The other all the time implies that he is helpful and patient even when there is no one else around.