How to use "hr./hrs" when describing time in the 24-hour clock?


Say, an event occurs between 15:00 to 16:00.

How do I write it?

15:00 - 16:00 hr.


15:00 - 16:00 hrs.

How do I use the "hr/.hrs" here? Do I even need them at all?

sue s.

Posted 2015-10-19T08:40:42.000

Reputation: 11

1This is not so much a question about the English language as about cultural differences. Different countries have different conventions; 15:00 1500 15h00 1500hr 3pm etc. It doesn't matter as long as it is clear. – Chenmunka – 2015-10-19T08:56:58.897



Here, you are talking about the timing of an event. In fact, the duration stating the time. So, it would be...

1500-1600 hr

Because you are actually telling - 1500 hr to 1600 hr.

One of the references I found is here

Use plural if you are talking about the number of hours. Say...

The event will run for 3 hours

Examples using 'hrs'

Maulik V

Posted 2015-10-19T08:40:42.000

Reputation: 66 188

1From a quick glance at a few online sources, it seems that "hours" (or "hrs") is optional. But if you don't use the colon, it seems necessary — "1500 hrs" to tag it as a time rather than an ordinary number. – Brian Hitchcock – 2015-10-19T09:02:26.340

It's interesting that an exact hour, e.g.15:00, is pronounced "fifteen hundred (hours)" in Military, even though military hours have only sixty minutes, just like civilian hours! For brevity's sake, one might think "at 15 hours" would work as well. Such are the mysteries of English, and of the military mind. – Brian Hitchcock – 2015-10-19T09:07:48.953

True, if the context is 'time' and if we are to use '24 hr' format, I don't prefer putting colons. Also good to note that in InE, we often refer to this as 'Railway Time Table' where time's mentioned in 24 hr format to avoid confusion. @BrianHitchcock – Maulik V – 2015-10-19T09:20:00.860

I'm also more comfortable with "1500 hrs". "1500 hr" looks a little weird to me. This makes me wonder where or in what dialects "1500 hr" is used (apparently the reference example you use is in Indian English). – Damkerng T. – 2015-10-19T09:34:37.003


For military time the 24 hour clock would use hrs for written communications as in, "The operation will begin at 1500 hrs." However, when speaking the hrs is not necessary. The Platoon Sergeant would say, "We move out at fifteen hundred; OPORD will be issued at oh four hundred with pre combat checks at thirteen thirty."

Dennis McLean

Posted 2015-10-19T08:40:42.000

Reputation: 1


In my opinion, hr/hrs is not necessary here. 15:00-16:00 is obviously referring to a start and stop time, and both hr/hrs would confuse me as they're redundant.

Synergy Zarka

Posted 2015-10-19T08:40:42.000

Reputation: 11