Protocol Tuesday: Do I Use Military Time on a Military Invitation?

Dear Robert,

My family is hosting a commissioning of my brother who is becoming a Second Lieutenant in the United States Army. Since he's entering the world of military time and 'twenty-four hundred hours" should we use military time on the invitation?

-- Jessica W., Athens, Georgia

Dear Jessica,

In the US Army's Protocol Guide they don't use 1400 hours They use at two o'clock See below:

--Robert Hickey, www.formsofaddress.info