There are two opportunities for date/time fields on message templates:

(1) If the field used on the request displays date only - the message template should only display the date and not date/time.  Or at least the designer of the message template should be able to limit what is displayed to date only.  Displaying the time is misleading at best. 

(2) For systems that are timezoned - the date and time should reflect the timezone of the individual receiving the message.  If this isn't practical because of the email grouping (cc & bcc) then include the timezone details in the message.  The preferred approach would be to display the date/time in the users timezone.  [Note:  Both Investec and Kroger have requested this enhancement].