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Today my iPhone reset its date to Jan 6, 1980. I Googled it and apparently it’s a very common problem. I found a ton of results for January 1980, and most if not all were in January 6th of 1980. The iPhone seems to get its “date” from cell towers, and I suppose one of the Verizon towers here is currently reset to Jan 6, 1980. I reset my phone, connected to Wi-Fi, and the problem was solved.

Later I started scrolling through some uncommon hashtags on Instagram and went to the oldest posts. When I looked at their time stamp it says they were posted 1772 weeks ago?! Sure enough: 1772 weeks ago was January 1980.

So what is the significance behind the January 1980 server time? It seems to come up a lot in glitches. Or is this just a Verizon specific thing and the photos on Instagram I saw were posted by users on Verizon cell towers?

Edit: After further Googling I found something on Wikipedia about January 6 1980 (the date my phone showed) as the “GPS Date Rollover bug” (GPS Epoch). iPhones use GPS to set their server time apparently. Doesn't seem to happen anytime soon though.

In the last few months before the year 2000, two other date-related milestones occurred that received less publicity than the then-impending Y2K problem.

The first problem was related to GPS devices: GPS dates are expressed as a week number and a day-of-week number, with the week number transmitted as a ten-bit value. This means that every 1,024 weeks (about 19.6 years) after 6 January 1980 (the GPS epoch), the date resets again to that date; this happened for the first time on 21 August 1999. To address this concern, modernized GPS navigation messages use a 13-bit field, which only repeats every 8,192 weeks (157 years), and will not return to zero until near the year 2137.

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Reset to default
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Every computer's internal clock counts from some particular start date, so if there's some kind of calendar glitch, you get whatever default date the computer thinks of as Year Zero.

Macs used to be January 1, 1900, but I think now they've moved up to 2001, just to be confusing.

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  • It used to be 1904 on some Macintoshes, my SE/30 would default to that regularly when its RTC battery was dying.
    – K.A.Monica
    Dec 31, 2013 at 8:42
  • The Unix epoch starts at January 1, 1970. That's what OS X uses internally as well. But if it detects clock problems, it might reset to year 2001 (which is "less scary" than 1970, I would guess).
    – u1686_grawity
    Dec 31, 2013 at 8:56
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    Interesting! Apparently the date I'm receiving is the "GPS epoch"... I'd assume iOS devices get their date from GPS and one of the satellites I'm connected to's date rolled over. Assuming this has happened on other iOS devices that then uploaded photos to Instagram, that explains why alot of Instagram photos have the upload date "Jan 6 , 1980"
    – Albert Renshaw
    Dec 31, 2013 at 16:35

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