National Traffic System


The following set of links provide references to find information about National Traffic System (NTS).
If you find any helpful links that are not included here, please use the E-mail link
at the bottom of the page to send the link(s) you would like to see added.

NTS Classes:

Jeff, KØRM, produced an on-the-air NTS class, presented on the Southern Colorado Traffic Net for a five-day period. The class was very informative for first-time traffic handlers, and was an excellent refresher course for seasoned traffic handlers. That class is now available for downloading via this web page. It’s presented in five separate files which can be printed from your web browser. View the National Traffic System (NTS) class.

NTS Links

GMT(Z) Time

Since NTS traffic is run in GMT (also known as Zulu[Z]) it is handy to be able to convert local time to GMT. GMT time is based on the twenty four hour clock. That is to say that from just after midnight until noon you use the time from your clock. For example 1:30 AM is 01:30 and 8:45 AM is 08:45. From noon until midnight you simply add twelve to the local 12 hour clock time. For example 1:30 PM is 13:30 and 8:45 PM is 20:45.

To convert local (in this case Mountain time) to GMT (or Zulu) you need to know if we are currently on Daylight Savings Time (MDT) or not (MST). If we are on Mountain Standard Time (MST) then you add seven (7) hours to the local time to get Zulu. If we are on MDT then you add six (6) hours to local time to get Zulu time.

This is all easy if you are in the morning or early afternoon because local plus offset (6 or 7) is still less than 24. If you were to originate a message at 8:45 PM, for example, it is a little more complex. If we are on MST, 8:45 PM, to convert to Zulu you convert to the twenty four hour clock (8:45 + 12 for PM = 20:45) then add the offset of MST (7) to local 24 hour time (20:44 + 7 = 27:45) and subtract 24 (maximum number of hours in one day) and you get 03:45 Z the next day.

The following are a few local times converted to Zulu, in table form. PLEASE take note of the MST MDT differences and that we did not include 00:01 to 12:59 (local) to keep the table smaller.

13:00 (1 PM) 12:00 19:00
14:00 13:00(1 PM) 20:00
15:00 14:00 21:00
16:00 (4 PM) 15:00 22:00
17:00 16:00 (4 PM) 23:00
18:00 17:00 00:00 (NEXT DAY)
19:00 (7 PM) 18:00 01:00 (Next day)
20:00 19:00 (7 PM) 02:00 (Next day)
21:00 20:00 03:00 (Next day)
22:00 (10 PM) 21:00 04:00 (Next day)
23:00 22:00 (10 PM) 05:00 (Next day)
00:00 23:00 06:00 (Next day)
01:00 00:00 07:00 (Next day)