Rotate axis text in python matplotlib

Question

I can\'t figure out how to rotate the text on the X Axis. Its a time stamp, so as the number of samples increase, they get closer and closer until they overlap. I\'d like

Answer 1

My answer is inspired by cjohnson318's answer, but I didn't want to supply a hardcoded list of labels; I wanted to rotate the existing labels:

for tick in ax.get_xticklabels():
    tick.set_rotation(45)