I tend to publish whatever you send me, at least as far as game notices go. Although I wrote that I would be 'somewhat draconian' about the submission guidelines, the reality is I can't be bothered to be that strict. However, please make it easy for players to figure out when your game is happening. ConstantCon is happening all over the world, and the international dateline can create some confusion. You'll get more players if you include not just your local date and time but the date and time in at least one time zone on the other side of the international dateline.
Here are a couple of widgets/websites that might make it easier for you to include this information in your announcements:
Event Time Announcer.
Wolfram Alpha Time Zone Converter.
Some random time zone converter.