Date 19 years 8 months wrong

[e***@aol.com]

My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?

As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.

Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida

Mont Vernon, NH

[Hum-rum]

Earl,

Main Menu -> Setup -> Time -> Menu -> Set Date: key in correct year.
--
Sigurd
N 59°56' E 10°42' (WGS 84)

Size and shape of the Earth (WGS 84)?
Garmin MapSource map sizes?
Garmin GPSmap 276C, GPS 12 MAP and GPS III (PLUS)?
See http://home.online.no/~sigurdhu

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

[e***@aol.com]

The suggestion by Sigurd was correct. I brought the GPS inside, put it
in Simulator mode, followed his procedure exactly, and it worked! I was
going to try the "Reset to factory defaults", but didn't want to loose
my waypoints.

Thank you very much. An easy fix once I was shown the way.

Earle Rich
Ortona Florida

[Hum-rum]

Earle,

This is also described in the "GPSmap 276C Owner's Manual" on page 83 of
Rev. B and C.
Latest revision is available from Garmin's web site.
--
Sigurd
N 59°56' E 10°42' (WGS 84)

Size and shape of the Earth (WGS 84)?
Garmin MapSource map sizes?
Garmin GPSmap 276C, GPS 12 MAP and GPS III (PLUS)?
See http://home.online.no/~sigurdhu

Post by e***@aol.com
The suggestion by Sigurd was correct. I brought the GPS inside, put it
in Simulator mode, followed his procedure exactly, and it worked! I was
going to try the "Reset to factory defaults", but didn't want to loose
my waypoints.
Thank you very much. An easy fix once I was shown the way.
Earle Rich
Ortona Florida

[j***@idirect.com]

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

Did the date and time correct itself when your GPSR got a lock?

It may not mean anything, but Aug 17, 2025 is <exactly> 1024 weeks
after Jan 1, 2006.

[Ron Lee]

Post by j***@idirect.com

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

Did the date and time correct itself when your GPSR got a lock?
It may not mean anything, but Aug 17, 2025 is <exactly> 1024 weeks
after Jan 1, 2006.

I would query Garmin since most likely it is a receiver issue.

Ron Lee

[Marc Brett]

Post by j***@idirect.com
It may not mean anything, but Aug 17, 2025 is <exactly> 1024 weeks
after Jan 1, 2006.

It means everything. The GPS signal in space has an ambiguous week number, so
if the firmware is up to date, then setting the date manually should be all
that's required to get the receiver working correctly.

There should be more fireworks and hand wringing when the 8-bit leap second
field rolls over at +128 s, but most of us won't be alive to see it...

Garmin *could* have used the leap second field to predict which 1024-week cycle
is current, but since Trimble patented the idea I guess they didn't bother.


http://www.navcen.uscg.gov/gps/geninfo/y2k/gpsweek.htm

THE GPS WEEK 1024 ROLLOVER

GPS System Time will roll over at midnight 21-22 August 1999, 132 days before
the Year 2000. On 22 August 1999, unless repaired, many GPS receivers will claim
that it is 6 January 1980, 23 August will become 7 January, and so on. Accuracy
of navigation may also be severely affected. Although it appears that GPS
broadcasts do contain sufficient data to ensure that navigation need not be
affected by rollover in 1999, it is not proven that the firmware in all
receivers will handle the rollovers in stride; some receivers may claim wrong
locations in addition to incorrect dates.

[Neil..]

Post by Marc Brett

Post by j***@idirect.com
It may not mean anything, but Aug 17, 2025 is <exactly> 1024 weeks
after Jan 1, 2006.

It means everything. The GPS signal in space has an ambiguous week number, so
if the firmware is up to date, then setting the date manually should be all
that's required to get the receiver working correctly.
There should be more fireworks and hand wringing when the 8-bit leap second
field rolls over at +128 s, but most of us won't be alive to see it...
Garmin *could* have used the leap second field to predict which 1024-week cycle
is current, but since Trimble patented the idea I guess they didn't bother.
http://www.navcen.uscg.gov/gps/geninfo/y2k/gpsweek.htm
THE GPS WEEK 1024 ROLLOVER
GPS System Time will roll over at midnight 21-22 August 1999, 132 days before
the Year 2000. On 22 August 1999, unless repaired, many GPS receivers will claim
that it is 6 January 1980, 23 August will become 7 January, and so on. Accuracy
of navigation may also be severely affected. Although it appears that GPS
broadcasts do contain sufficient data to ensure that navigation need not be
affected by rollover in 1999, it is not proven that the firmware in all
receivers will handle the rollovers in stride; some receivers may claim wrong
locations in addition to incorrect dates.

Just a quick comment, based on an old Motorola Manual for an oncore gps
receiver, When setting the date manually you MUST be completely out-of-gps
coverage otherwise the GPS signal will over-ride your setting.
I have seen several Motorola GPS oncore unit's suffer this problem of
displaying 1024 weeks in the future and resetting the date seems to sort
them out, alternatively, if you can, a FULL GPS reset (if available) should
reset the unit, but it will take a while to relock to the satellites.

Neil..

[j***@idirect.com]

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

Did the date and time correct itself when your GPSR got a lock?

It may not mean anything, but Aug 17, 2025 is <exactly> 1024 weeks
after Jan 1, 2006.

[Bob]

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

Earle,

I have a feeling that it has something to do with the leap second and
the fact that your GPS is rather old. The firmware may not have been
able to handle it.

Have you tried a master reset? (Menu/Power On)

Bob

[Hum-rum]

Bob,

What do mean by "rather old"?
The Garmin GPSmap 276C receiver was introduced on February 12, 2004 and is
still in production!
--
Sigurd
N 59°56' E 10°42' (WGS 84)

Size and shape of the Earth (WGS 84)?
Garmin MapSource map sizes?
Garmin GPSmap 276C, GPS 12 MAP and GPS III (PLUS)?
See http://home.online.no/~sigurdhu"


Bob" <***@verizon.net> skrev i melding news:***@g47g2000cwa.googlegroups.com...
<snip>

Post by Bob
I have a feeling that it has something to do with the leap second and
the fact that your GPS is rather old. The firmware may not have been
able to handle it.
Have you tried a master reset? (Menu/Power On)
Bob

[Marc Brett]

Post by Hum-rum
Bob,
What do mean by "rather old"?
The Garmin GPSmap 276C receiver was introduced on February 12, 2004 and is
still in production!

Then the firmware programming is crap. If it was introduced in 2004, it should
be able to resolve the week number ambiguity by refusing to report a date
earlier than 2004. After 2019, ambiguity creeps in, but there's no excuse for
misreporting the date in the year 2006.

[Darren Dunham]

Post by Marc Brett
Then the firmware programming is crap. If it was introduced in 2004, it should
be able to resolve the week number ambiguity by refusing to report a date
earlier than 2004. After 2019, ambiguity creeps in, but there's no excuse for
misreporting the date in the year 2006.

I thought in this case it didn't report a date earlier than 2004. It
somehow thought it was the next epoch, not the previous one.

[Dominic Sexton]

Post by Darren Dunham

Post by Marc Brett
Then the firmware programming is crap. If it was introduced in 2004, it should
be able to resolve the week number ambiguity by refusing to report a date
earlier than 2004. After 2019, ambiguity creeps in, but there's no excuse for
misreporting the date in the year 2006.

I thought in this case it didn't report a date earlier than 2004. It
somehow thought it was the next epoch, not the previous one.

It was - August 2025.

[matt weber]

Post by e***@aol.com
My recently acquired Garmin 276C has been great. However, on January 1,
the date shown was August, 2025. Not that big a deal except for the
puzzlement. Any ideas what could cause this and perhaps how to fix it?
As a "snowbird", volunteering for the US Army Corps of Engineers in
Florida, please reply to my email address as well as to this group.
Earle Rich
Photographer and Water Safety Instructor
Ortona, Florida
Mont Vernon, NH

19 years =19 x 52=988 weeks, 24+12=36 weeks, just about 8 months.
GPS dates roll over at the rate of every 1024 weeks, and an interval
of 1024 weeks in GPS is called an Epoch.

For some reason your GPS thinks it is in the next Epoch.
(1024 weeks in a epoch), a number of GPS had problems with the last
Epoch rollover, which was in 1999. The fix for most of them was to
induce amnesia (take out the batteries and allow the internal memory
to go blank), then put batteries in, and allow the unit to obtain a
fresh almanac.

Take the batteries out, wait 30 minutes, put the batteries back, and
let it collect a new almanac. That should fix it. If it doesn't, call
garmin.