Display custom field as publish date?

I’d like the date an editor enters in a custom field to be displayed instead of the published date for posts in a particular category. I don’t have a lot of coding experience, so I’m hoping someone more experienced can help!

I’m posting notices about future maintenances along with notices about current activities. I’d like the date next to the post title for maintenances to display the actual date the maintenance will occur, but display the publish date for current activities. I could probably use an events plugin to post the maintenances, but I’d like the maintenance posts to look exactly like the others (except the date).

Running WordPress 3.5.1. Theme is Graphene. Site is http://www.rochester.edu/it/notices.