Changing order of posts

Trying to utilize WP as a simple web-based tool for my client to enter calendar events:

http://www.aromaceuticals.com/events

I need these entries to appear in the reverse order that WP defaults to, and there doesn’t seem to be any option to change that in the control panel (which I find pretty strange). I’m obviously using a truncated version of WP in my own template, but I wonder if there is some code I could add to reverse the order of entries displayed?

Thanks in advance for any help!