# The most useless accessory in my car is now even more useless **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 3, 2012, 1:54am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612 "2012-03-03T01:54:47Z")\ **Posts on this page:** 20\ **Page:** 9
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [November 10, 2016, 4:08pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/161 "2016-11-10T16:08:30Z")
This is my favorite thread of all time. And what you’re seeing now is logical, thankfully. Feb 28 was the 59th day of the year. Today, Nov 10, is the 315th day of the year. 315-59=256. 256 is the size of an 8 bit register. So the day of the month was being stored as an 8 bit value, which finally rolled over to 1 again a few weeks ago, and became displayable again. Of course, you’re probably into a perpetual February 1-256 day cycle now. I’d expect the same FEB 30 stuff to start again on Saturday, and since you’re never getting past February, the year will never roll over either, and you’ll finally wind up back on FEB 28 on July 24th next year ---
**Author:** ![Asimovian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asimovian/32/172_2.png) [@Asimovian](https://boards.straightdope.com/u/Asimovian)\ **Post date:** [November 10, 2016, 4:59pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/162 "2016-11-10T16:59:09Z")
> [@muldoonthief](#): > > Of course, you’re probably into a perpetual February 1-256 day cycle now. I’d expect the same FEB 30 stuff to start again on Saturday, and since you’re never getting past February, the year will never roll over either, and you’ll finally wind up back on FEB 28 on **July 24th next year** \ ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [November 10, 2016, 7:17pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/163 "2016-11-10T19:17:00Z")
I like the 8-bit / 256 days theory. I have a file on my laptop where I’ve been keeping track of what the display shows every 10 days, but unfortunately the last notes I made were on Sept 27. I really should have been paying more attention in October! Working back from today, I’m guessing that on Oct 13 (day 256 since Feb 1) it was showing FEB °6 then the next day rolled back over to FEB 01. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [November 10, 2016, 8:01pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/164 "2016-11-10T20:01:49Z")
> [@Shoeless](#): > > I like the 8-bit / 256 days theory. I have a file on my laptop where I’ve been keeping track of what the display shows every 10 days, but unfortunately the last notes I made were on Sept 27. I really should have been paying more attention in October! Working back from today, I’m guessing that on Oct 13 (day 256 since Feb 1) it was showing FEB °6 then the next day rolled back over to FEB 01. Yeah, you’ll have to see what happens on June 26-27 next year to confirm this - that will be 512 days from Feb 1. Stay up till midnight to be sure. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 10, 2016, 8:21pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/165 "2016-11-10T20:21:03Z")
Don’t ever sell this car! ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 10, 2016, 9:36pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/166 "2016-11-10T21:36:57Z")
> [@davidm](#): > > Don’t ever sell this car! Someday his battery is going to die, and then what will you do? ---
**Author:** ![wguy123](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wguy123/32/3161_2.png) [@wguy123](https://boards.straightdope.com/u/wguy123)\ **Post date:** [November 10, 2016, 11:15pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/167 "2016-11-10T23:15:06Z")
> [@beowulff](#): > > Someday his battery is going to die, and then what will you do? Did you ever see the Seinfeld where George bought the Frogger game and wanted to move it with his high score intact? It can be done! ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [November 10, 2016, 11:28pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/168 "2016-11-10T23:28:06Z")
> [@beowulff](#): > > Someday his battery is going to die, and then what will you do? Actually IIRC that’s what killed the streak in 2012. I had to take my car into the shop for something, and they disconnected the battery while they were working on it. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 11, 2016, 2:16am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/169 "2016-11-11T02:16:06Z")
> [@wguy123](#): > > Did you ever see the Seinfeld where George bought the Frogger game and wanted to move it with his high score intact? It can be done! Didn’t that end up with the game smashed to pieces in the middle of the street? ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [November 11, 2016, 4:53pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/170 "2016-11-11T16:53:28Z")
There are devices that applies voltage while the battery is disconnected and let you preserve all radio/clock other memory settings - [here’s one](https://www.amazon.com/Kastar-Hand-Tools-Computer-Memory/dp/B000UZQUS6). I know the last time I bought a new battery with free installation at Autozone(?) they just attached one of those portable chargers to the power port which worked to preserve the settings as well. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [May 31, 2017, 2:55am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/171 "2017-05-31T02:55:38Z")
> [@davidm](#): > > Don’t ever sell this car! Sad news… while I haven’t sold the Santa Fe, I did buy a new car this weekend. (Another Hyundai, as it turns out. They were practically _giving away_ Sonatas this month. It was too hard to pass up a deal like that.) The Santa Fe will probably stay in the family for a while… a couple of the grandkids are driving age now :eek: so we’ll fix it up and either hand it down or sell it cheap to one of them. Maybe I shouldn’t tell them about the date display and let them find out for themselves when next leap year rolls around. ---
**Author:** ![purplehearingaid](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@purplehearingaid](https://boards.straightdope.com/u/purplehearingaid)\ **Post date:** [May 31, 2017, 3:18am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/172 "2017-05-31T03:18:44Z")
> [@Shoeless](#): > > It’s a 2003 Hyundai Santa Fe. > > Yeah, there is. I just want to see where it goes on it’s own. It going back to the future ! ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [May 31, 2017, 3:27am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/173 "2017-05-31T03:27:16Z")
> [@Shoeless](#): > > The Santa Fe will probably stay in the family for a while… a couple of the grandkids are driving age now :eek: so we’ll fix it up and either hand it down or sell it cheap to one of them. Maybe I shouldn’t tell them about the date display and let them find out for themselves when next leap year rolls around. You need to give it to someone who’s willing to post to this thread! So my vote is to tell them about the display, have a good laugh and then dangle the keys as you ask them if they can be relied on for some updates for your old buddies here. And I woul… oh, geez, is it FEB °0 already? I gotta run! ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [May 31, 2017, 5:56am UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/174 "2017-05-31T05:56:28Z")
> [@Shoeless](#): > > I like the 8-bit / 256 days theory. Early in this thread someone mentioned the Maya calendar as a joke. Coincidentally, one of the two parallel Maya systems is based on a [260-day cycle!](http://calendars.wikia.com/wiki/Maya_calendar) > [@](#): > > With all twenty named days used, these now began to repeat the cycle while the numbered portion continued, so the next day after 7 Ajaw was 8 Imix’. The repetition of these interlocking 13- and 20-day cycles therefore took 260 days to complete (that is, for every possible combination of number/named day to occur once). > > The exact origin of the Tzolk’in is not known, but there are several theories. One theory is that the calendar came from mathematical operations based on the numbers thirteen and twenty, which were important numbers to the Maya. The number twenty was the basis of the Maya counting system, taken from the number of human fingers and toes. (See Maya numerals). Thirteen symbolized the number of levels in the Upperworld where the gods lived, and the number of “major joints” on the human body (three per limb, plus the neck). The numbers multiplied together equal 260. > > Another theory is that the 260-day period came from the length of human pregnancy. This is close to the average number of days between the first missed menstrual period and birth, unlike Naegele’s rule which is 40 weeks (280 days) between the last menstrual period and birth. It is postulated that midwives originally developed the calendar to predict babies’ expected birth dates. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [May 31, 2017, 12:54pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/175 "2017-05-31T12:54:56Z")
> [@digs](#): > > You need to give it to someone who’s willing to post to this thread! > > So my vote is to tell them about the display, have a good laugh and then dangle the keys as you ask them if they can be relied on for some updates for your old buddies here. > > And I woul… oh, geez, is it FEB °0 already? I gotta run! Maybe I should put it up for sale in the Marketplace forum, give the Dopers first crack at it. 😉 ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [July 21, 2017, 1:37pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/176 "2017-07-21T13:37:51Z")
Bump - hey **Shoeless** , if my math from several posts back is correct, and you haven’t reset anything, the car should be displaying “Feb 25” today, and will hit Feb 29 on Tuesday. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [July 21, 2017, 4:01pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/177 "2017-07-21T16:01:54Z")
> [@muldoonthief](#): > > Bump - hey **Shoeless** , if my math from several posts back is correct, and you haven’t reset anything, the car should be displaying “Feb 25” today, and will hit Feb 29 on Tuesday. If he hasn’t sold it, which he was planning to do. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [July 21, 2017, 4:40pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/178 "2017-07-21T16:40:26Z")
> [@davidm](#): > > If he hasn’t sold it, which he was planning to do. To one of his grandkids though, so hopefully he’s still keeping an eye on the calendar for our sake. He owes us _that_ much. 🙂 ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [July 21, 2017, 7:39pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/179 "2017-07-21T19:39:30Z")
I still have the car, but probably not for too much longer. Unfortunately the date display got reset a while back when I was trying to troubleshoot why the power mirrors were no longer working. I wasn’t sure which fuse was for the mirrors… The fuse diagram was confusing. It might have been the same one as the radio (which was working fine), or a couple of others…I wound up pulling and checking them all, and then later noticed the date display had reset. ---
**Author:** ![Channing\_Idaho\_Banks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/channing_idaho_banks/32/250_2.png) [@Channing\_Idaho\_Banks](https://boards.straightdope.com/u/Channing_Idaho_Banks)\ **Post date:** [July 21, 2017, 8:03pm UTC](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612/180 "2017-07-21T20:03:48Z")
That means you are going to have to keep the car for a long time! [Previous page](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612.md?page=8) [Next page](https://boards.straightdope.com/t/the-most-useless-accessory-in-my-car-is-now-even-more-useless/614612.md?page=10)