In U.S. military time, 1700 hours is equal to 5:00 p.m. when expressed in standard time. The military uses a 24-hour clock that begins at 0000, which corresponds to midnight, and ends at 2359, or 11:59 p.m.
When personnel stationed in one time zone communicate with personnel in another time zone, they reference what the U.S. military refers to as "Zulu" time. This corresponds to the time zone in which Greenwich, England is located. The military divides the globe into 24 time zones, each corresponding to a letter. The letter assigned to Greenwich is Z, which is called "Zulu" in the military alphabet. In the military, each letter of the alphabet is assigned a word to avoid errors in communication.