UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Reset date format for all users

My default date format is m/d/y so new users will see that date format in the forums. Unfortunately, many users were apparently imported with the d/m/y format. Is there a way to change everybody over to m/d/y without having to log in as each user and change the setting in their My Preferences screen?

Thank you