GPS and April 6th 2019

MartynG said:
Which, for those too young to remember it, was a lot of scare mongering followed by a non event.
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... because a large number of I.T. people worked quite hard and earned some good overtime pay to make sure that it was a non-event.
If we had done nothing, several really quite important systems would have stopped working, or produced some very strange results.

There’s going to be something similar on Sat 20th November 2286 when the Unix date rolls over, but that will be someone else’s problem to sort out :)

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FlowerPower said:
... because a large number of I.T. people worked quite hard and earned some good overtime pay to make sure that it was a non-event.
If we had done nothing, several really quite important systems would have stopped working, or produced some very strange results.
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Really?
 
MartynG said:
Really?
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Which bit ... the overtime? or the Bank’s mainframe that would not have paid any standing orders because it thought the setup dates were 99 years into the future?

It’s true that things did get a bit over-hyped - some reports suggested that volcanic lava would be flowing down the streets.
But the “do nothing” option would have most probably have resulted in chaos.

First thing we did was to set the date on a test system simply to “see what would happen” in paralell with a bunch of people doing the proper analysis and remediation ...

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Like FlowerPower (I'm assuming) I was heavily involved in the run up to the Millenium

The media frenzy was full of nonsense, of course, but there WAS a very real issue that if nothing had been done would have caused utter chaos as thousands of legacy systems fell over. A lot of people did a lot of hard work to make sure that it was, indeed, a non-event and it get's up my nose sideways when it's dismissed as some sort of hoax

Rant over :cool:
 
Yep, the millennium bug was only a non event because everyone involved did their job and fixed the systems that would have been affected otherwise.

Back to the GPS date rollover, I'm assuming that most modern (ie in the last 10-15 years) gps recievers can cope with this, and its only the really old stuff that might have trouble? Does Anyone know?
 
julians said:
Back to the GPS date rollover, I'm assuming that most modern (ie in the last 10-15 years) gps recievers can cope with this, and its only the really old stuff that might have trouble? Does Anyone know?
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Really old stuff has been through the last week-number rollover already, so if you’re still using it now then it’s obviously correctly programmed to handle it. Chips designed since then might or might not handle it properly. Roll-over is part of the protocol design so it shouldn’t have caught them by surprise, but...

A few devices started failing late last year, because for some reason they handled the week number in decimal and fell over at week 999 instead of week 1023.

Pete
 
My IT & telecoms company has 2,500 contracts including some hospitals. It took many months of planning and checking, and on the night of the 31st December we had partial staffing in the office with all the engineers on standby in case.

The only casualties were a handful of companies which had refused to use the checks we'd recommended. We didn't really smile....
 
Garmin released a new legacy update 29th Jan 19 which specifically updates 19x GPS.

I’m guessing this is in response to the date issue. I’ve emailed them to check that is the case and will update it anyway.
 
I experienced the last rollover on passage to L'Aberwrac'h.
It was worrying to notice that I was losing satellites as they fell to the horizon, but new ones were not forthcoming.
But I found my way alright and moored next to a single-hander on his way to the Baltic with a boxer dog. I mentioned the GPS to him and he was clued up, explained what it was about and said it should be alright in the morning.
Indeed it was.
 
Reply from Garmin....

“What is the GPS Week Number Rollover (WNRO)?

The GPS system is world renowned for its ability to provide accurate and reliable positioning and timing information worldwide. The GPS satellites transmit to users the date and time accurate to nanoseconds. However, back in 1980, when the GPS system first began to keep track of time, the date and time was represented by a counter that could only count forward to a maximum of 1024 weeks, or about 19.7 years. After 1024 weeks had elapsed, this counter “rolled over” to zero, and GPS time started counting forward again. This first rollover occurred in August of 1999. The second rollover will occur on April 6, 2019.

What is the Effect of a GPS Week Number Rollover Issue?

For GPS devices that are affected, after the rollover occurs, an incorrect date and time will be displayed. This incorrect time will also be used to timestamp track logs, compute sunrise and sunset, and other functions that rely upon the correct date and time. However, the positioning accuracy will not be affected. The device will continue to deliver the same positioning performance as before the rollover.

Is My Device Affected?

For many years, Garmin has anticipated and prepared for this event. Regardless, Garmin has been performing exhaustive testing of current and legacy devices to determine if they will be affected by the GPS week number rollover. Our testing shows the vast majority of Garmin GPS devices will handle the WNRO without issues.”
 
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