Formatting Time

P.M. and A.M.:

We require the standard deployment of TIME punctuation. The longer, "classic" installation of time formatting is the rule since it's easier to read/spot on a web page. Therefore:

This –  12:00 to 1:30 p.m.

Versus this – 12 pm – 1:30 pm

And certainly not this – 12-1 pm

Using a dash instead of "to" is acceptable:

12:00 p.m. – 1:30 p.m.

Which format below do you find easier to read/spot the time?

Normandale Community College will host a Campus Open House on Tuesday, April 23, 2013 from 5-7 pm. This is a great opportunity for you to learn more about Normadale. What's more, if you decide to apply online during open house, you can save the $20 application fee.

or this:

Normandale Community College will host a Campus Open House on Tuesday, April 23, 2013 from 5:00 p.m. to 7:00 p.m. This is a great opportunity for you to learn more about Normadale. What's more, if you decide to apply online during open house, you can save the $20 application fee.