GPS uses a week-numbering calendar

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GPS uses a week-numbering calendar

Amos Shapir-2

It seems that GPS uses a special calendar: instead of months and years, it uses a running count of weeks.  The problem is, it defines only 10-bits for this counter, so the number of weeks rolls back to 0 after 1024 weeks, or about 20 years; some older systems cannot cope with this, creating a bug similar to Y2K.

The epoch of this calendar is Jan 1. 1980 (1st Sunday of the 1980's), which means the roll-over had already happened once before in Aug 1999; it seems some programmers (like the original designers) could not believe their programs would still be in use 20 years after they were deployed.

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Amos Shapir
 
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13520.01.28 - Re: GPS uses a week-numbering calendar

Litmus UCC

28 ONE-Aries♈ 13520 UCC

Amos!

That's interesting, thanks for pointing that out. I remember the Y2K nonsense as I was working in the corporate world at the time. Many consultants got rich on the back of that one!! :D

In the UCC we have the (average) 24,000 year cycle of the Great Year (Precessional Cycle) driving the year numbers so hopefully we won't have this problem! ;)

Peace, love and freedom

Litmus

Litmus A Freeman
Creator of the Universal Celestial Calendar (UCC)
http://universalcelestialcalendar.com
On 4/18/19 3:51 PM, Amos Shapir wrote:

It seems that GPS uses a special calendar: instead of months and years, it uses a running count of weeks.  The problem is, it defines only 10-bits for this counter, so the number of weeks rolls back to 0 after 1024 weeks, or about 20 years; some older systems cannot cope with this, creating a bug similar to Y2K.

The epoch of this calendar is Jan 1. 1980 (1st Sunday of the 1980's), which means the roll-over had already happened once before in Aug 1999; it seems some programmers (like the original designers) could not believe their programs would still be in use 20 years after they were deployed.

--
Amos Shapir
 
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Re: 13520.01.28 - Re: GPS uses a week-numbering calendar

Brij Bhushan metric VIJ
Amos, sirs:
> .....this calendar is Jan 1. 1980 (1st Sunday of the 1980's), which means the roll-over had already happened once before in Aug 1999; it seems some programmers (like the original designers)........
Yes, to me this appears, THIS IS BUILT to work on “Binary count of 2^10”=1024 lasting for 19yesrs+36weekd; after its last roll over, next ROLL OVER is expected to start in late April/early May 2019. it might have just started, I suppose - likely used as GPS counter?
THIS IS MY INSTINCTIVE GUESS, and true I had not heard of this earlier. 
Regards,
Flt Lt Brij Bhushan VIJ (Retd.), IAF ✈️
Friday, 2019 April 19H06:66 (decimal)

Sent from my iPhone

On Apr 19, 2019, at 02:45, Litmus UCC <[hidden email]> wrote:

28 ONE-Aries♈ 13520 UCC

Amos!

That's interesting, thanks for pointing that out. I remember the Y2K nonsense as I was working in the corporate world at the time. Many consultants got rich on the back of that one!! :D

In the UCC we have the (average) 24,000 year cycle of the Great Year (Precessional Cycle) driving the year numbers so hopefully we won't have this problem! ;)

Peace, love and freedom

Litmus

Litmus A Freeman
Creator of the Universal Celestial Calendar (UCC)
http://universalcelestialcalendar.com
On 4/18/19 3:51 PM, Amos Shapir wrote:

It seems that GPS uses a special calendar: instead of months and years, it uses a running count of weeks.  The problem is, it defines only 10-bits for this counter, so the number of weeks rolls back to 0 after 1024 weeks, or about 20 years; some older systems cannot cope with this, creating a bug similar to Y2K.

The epoch of this calendar is Jan 1. 1980 (1st Sunday of the 1980's), which means the roll-over had already happened once before in Aug 1999; it seems some programmers (like the original designers) could not believe their programs would still be in use 20 years after they were deployed.

--
Amos Shapir