What is the best time of day to take flying lessons in Denver, CO?

I am taking flying lessons in Denver and I would like to know the best time of day to do that.

Assuming you are just getting your private certificate, which is what it sounds like, time of day will be irrelevant. What your timing will depend on is weather. Besides, you will have to log a few night hours anyway.

Given the choice, I'd shoot for early morning. In the summer, that is probably the best time to fly - nice, relatively quiet, air is still calm from the night, etc. Its a good time.