USE OF JULIAN DATE AND GPS ZULU TIME

TM 11-5820-890-10-8

USE OF JULIAN DATE AND GPS ZULU TIME

4.4.

Two- Digit Julian Date

4.4a.

Julian calendar days are normally numbered 1 through 365 or 366, with

DEFINITION

the year appended as a fourth digit.

The SINCGARS radio uses a special two-digit form of Julian Date as a

TWO-DIGIT DATE

part of sync time. The two-digit Julian Date begins with 01 for 1

January and continues through to 00, repeating as necessary to cover

the entire year.

In that the two-digit Julian year ends on 65, or 66 for leap year, every 1

1 JANUARY CHANGE

January the Julian Date must be changed to 01. This can be done by:

(1)

The NCS sending an ERF;

(2)

Operators reloading time directly from an ANCD or PLGR; or,

(3)

Operators manually changing the date in the radio by using the RT

keypad.

Dates displayed in the ANCD and PLGR take the form of

CONVERSION

Day-Month-Year (23-09-95). When these dates are loaded into a

SINCGARS radio, they are automatically converted to the correct

two-digit Julian Date needed by the radio.

Appendix A to this manual provides two-digit Julian Date calendars for

APPENDIX

both regular and leap years.

If your net were the only one operating in the FH mode, your NCS could

IMPORTANCE

select any two-digit date for net opening. Technically, the radio will

work on any two-digit date. The importance of using the prescribed

two-digit Julian Date is when there are other FH nets operating and

you may need to contact them or they may need to contact you. Unless

both nets have the same two-digit date as a part of sync time, they

cannot communicate.

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