# Why was my phone too dumb to handle daylight saving time?
**URL:** https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820
**Category:** Factual Questions
**Created:** [March 10, 2008, 9:15am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820 "2008-03-10T09:15:32Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@zuma](https://boards.straightdope.com/u/zuma)
#### Post date: [March 10, 2008, 9:15am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/1 "2008-03-10T09:15:32Z")
So on sunday, about 5:30 p.m., I noticed that my cell phone was still displaying 4:30 p.m. Now I’ve never really noticed it changing over before, but I sure never noticed it NOT changing, so I assume all the cell phones I’ve owned til now did it.
After I turned it off and on again, it displayed the correct time, as I was pretty sure it checks in on the time whenever it initially powers up. Getting off planes in different time zones has borne this out.
So do they only check the time when they first power on, then use their internal clock to keep up? I always assumed they’d maybe ask the time every x minutes or so. I’d also assume that the cell provider (sprint) would at the very least send an “update your time, phones” command at daylight savings time.
Anyone else notice this, or know how cell phones handle time keeping?
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### Author:  [@Subway\_Prophet](https://boards.straightdope.com/u/Subway_Prophet)
#### Post date: [March 10, 2008, 1:27pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/2 "2008-03-10T13:27:23Z")
My phone, a Sanyo VI-2300 on the Sprint network (bleh), seems to check the time when it’s powered on, and when it moves between cells.
Which sort of makes sense to me - why check for DST rollover every x minutes when it only happens twice a year?
I think a much better solution would be to use a time zone-based clock-changing strategy like desktop computers do. But the cell phone biz is full of annoying technological shortcuts, so it doesn’t surprise me any more when something seemingly obvious isn’t implemented.
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [March 10, 2008, 1:35pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/3 "2008-03-10T13:35:42Z")
[QUOTE=Subway Prophet]
…why check for DST rollover every x minutes when it only happens twice a year?
[/QUOTE]
It’s not just checking for DST rollover. The phone’s internal clock is not perfect and will drift, just like any other quartz or electronic clock. A periodic update keeps it accurate, like those atomic radio clocks.
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### Author:  [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)
#### Post date: [March 10, 2008, 2:25pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/4 "2008-03-10T14:25:12Z")
I’ve noticed when driving across country that my phone will change automatically when I enter a new time zone. Each time the phone checks in with a tower, the date/time are updated. My guess is that the problem is not with your phone, but with your provider, who didn’t read the memo about DST being earlier this year and upgrade the software in the towers.
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### Author:  [@Subway\_Prophet](https://boards.straightdope.com/u/Subway_Prophet)
#### Post date: [March 10, 2008, 2:34pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/5 "2008-03-10T14:34:12Z")
[QUOTE=CookingWithGas]
It’s not just checking for DST rollover. The phone’s internal clock is not perfect and will drift, just like any other quartz or electronic clock. A periodic update keeps it accurate, like those atomic radio clocks.
[/QUOTE]
If the quartz in my phone is anything like the quartz in my Timex, it only needs to correct for drift once or twice a year anyway.
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### Author:  [@mks57](https://boards.straightdope.com/u/mks57)
#### Post date: [March 10, 2008, 2:40pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/6 "2008-03-10T14:40:44Z")
The problem with putting the local time zone logic in the phone is that it’s a complicated mess, subject to change every time some government, somewhere in the world, gets a bright idea about improving things. It’s simpler for the cellular base station to tell the phone the local time.
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### Author:  [@Great\_Dave](https://boards.straightdope.com/u/Great_Dave)
#### Post date: [March 10, 2008, 2:46pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/7 "2008-03-10T14:46:11Z")
My wifet have and I share an account with Verizon, but have different brand phones. Mine updated automatically, without turning it off and back on, but hers did not.
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### Author:  [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)
#### Post date: [March 10, 2008, 5:11pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/8 "2008-03-10T17:11:26Z")
I’d guess that your phone will be smart enough to handle DST in a week, when it’s supposed to be.
It’s actually the _United States Government_ that’s too dumb to handle Daylight Saving Time.
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### Author:  [@GaryM](https://boards.straightdope.com/u/GaryM)
#### Post date: [March 10, 2008, 7:07pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/9 "2008-03-10T19:07:53Z")
My ATT serviced Blackberry updated automatically. My BILs Sprint phone needed to be turned off, then back on for it to update.
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### Author:  [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)
#### Post date: [March 10, 2008, 8:51pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/10 "2008-03-10T20:51:07Z")
Simple answer: as long as the phone isn’t being handed off to a new tower, or talking to a tower to accomplish something like a phone call, receipt of a call, message or text, etc., it doesn’t get it’s time display updated. Presumably, different phone companies have different software code on the issue. I noticed my Sprint phone didn’t automatically update overnight; presumably Sprint prefers its phones not to be spending power sending out signals on a regular basis.
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### Author:  [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)
#### Post date: [March 10, 2008, 9:06pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/11 "2008-03-10T21:06:00Z")
[QUOTE=Subway Prophet]
If the quartz in my phone is anything like the quartz in my Timex, it only needs to correct for drift once or twice a year anyway.
[/QUOTE]
It probably isn’t. Lousy quartz oscillators are a lot cheaper than good ones (on a relative scale), so for something that expects to get frequent updates, they use the cheap ones. I’ve got a DVD/VCR player that’s supposed to sync to the clock broadcast on PBS stations, but since I don’t have it hooked up to cable, it drifts a lot. Like 80 minutes in the past year and a half.
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### Author:  [@atomicbadgerrace](https://boards.straightdope.com/u/atomicbadgerrace)
#### Post date: [March 10, 2008, 9:07pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/12 "2008-03-10T21:07:46Z")
My phone was running on the Sprint network at my home when DST kicked in. I was curious to see if it would update at 2 or not. 1:59 came and went, then it switched over to 2:00. After about 5 seconds, it updated to show 3:00.
I assumed it went to 2:00 briefly to allow for anyone who had set an alarm to wake them up at 2; the idea that it was waiting for a tower update didn’t even cross my mind, but that’s probably it.
Only then did I realize that I had to go through the house and change the other clocks. :smack:
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### Author:  [@Ignatz](https://boards.straightdope.com/u/Ignatz)
#### Post date: [March 10, 2008, 11:55pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/13 "2008-03-10T23:55:29Z")
[QUOTE=CookingWithGas]
It’s not just checking for DST rollover. The phone’s internal clock is not perfect and will drift, just like any other quartz or electronic clock. A periodic update keeps it accurate, like those atomic radio clocks.
[/QUOTE]
I have an battery-powered atomic clock on my office desk and I had to reset it manually today. Why’s that?
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### Author:  [@GaryM](https://boards.straightdope.com/u/GaryM)
#### Post date: [March 11, 2008, 1:48am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/14 "2008-03-11T01:48:35Z")
[QUOTE=Ignatz]
I have an battery-powered atomic clock on my office desk and I had to reset it manually today. Why’s that?
[/QUOTE]
Here’s two possible answers.
1. The clock didn’t receive a good signal.
2. The manufacturer chose to program the clock’s chip with the start and stop dates of DST rather than include the programming to pick up that part of the data stream from Ft. Collins. In this case the clock would be unaware of the change in timing.
Some of my digital clocks updated while others did not. I have an analog clock that actually has a switch on the back to select and deselect DST. Handy to have if you live in Arizona.
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### Author:  [@Boozahol\_Squid\_P.I](https://boards.straightdope.com/u/Boozahol_Squid_P.I)
#### Post date: [March 11, 2008, 1:53am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/15 "2008-03-11T01:53:46Z")
[QUOTE=GaryM]
Here’s two possible answers.
1. The clock didn’t receive a good signal.
2. The manufacturer chose to program the clock’s chip with the start and stop dates of DST rather than include the programming to pick up that part of the data stream from Ft. Collins. In this case the clock would be unaware of the change in timing.
Some of my digital clocks updated while others did not. I have an analog clock that actually has a switch on the back to select and deselect DST. Handy to have if you live in Arizona.
[/QUOTE]
Does your analog clock normally update for DST? That’s gotta look cool at 1:59:59.
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### Author:  [@GaryM](https://boards.straightdope.com/u/GaryM)
#### Post date: [March 11, 2008, 1:59am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/16 "2008-03-11T01:59:04Z")
Nope, that one has the switch to select DST. I need to take out the battery and select DST, then replace the battery. When the clock receives the signal from Ft. Collins the hands will spin around and stop on the correct time.
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### Author:  [@aktep](https://boards.straightdope.com/u/aktep)
#### Post date: [March 11, 2008, 2:18am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/17 "2008-03-11T02:18:01Z")
[QUOTE=iamthewalrus(:3=]
I’d guess that your phone will be smart enough to handle DST in a week, when it’s supposed to be.
It’s actually the _United States Government_ that’s too dumb to handle Daylight Saving Time.
[/QUOTE]
A week? It’s “supposed to be” first weekend in April.
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### Author:  [@astro](https://boards.straightdope.com/u/astro)
#### Post date: [March 11, 2008, 7:21am UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/18 "2008-03-11T07:21:09Z")
In some cell phones there is a sub-menu under one of the setup parameters to allow the phone to recalibrate time to the cell tower signal or not. I would imagine in the phones that are not changing this option is toggled off. Check your settings.
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### Author:  [@Merhouse](https://boards.straightdope.com/u/Merhouse)
#### Post date: [March 15, 2008, 9:01pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/19 "2008-03-15T21:01:32Z")
[QUOTE=iamthewalrus(:3=]
I’d guess that your phone will be smart enough to handle DST in a week, when it’s supposed to be.
It’s actually the _United States Government_ that’s too dumb to handle Daylight Saving Time.
[/QUOTE]
I have a Nokia which sets time zones by the offset from GMT, which would be great if I lived in a time zone that was consistently the same number of hours from GMT. However, NJ has seceeded from GMT for a couple of weeks 🙂
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### Author:  [@Musicat](https://boards.straightdope.com/u/Musicat)
#### Post date: [March 15, 2008, 9:35pm UTC](https://boards.straightdope.com/t/why-was-my-phone-too-dumb-to-handle-daylight-saving-time/440820/20 "2008-03-15T21:35:30Z")
I have no special technical knowledge about cellphones, but I was curious about how the Caller ID time on the various landline-connected phones gets updated. All my displays showed the wrong time after 2AM on the day of DST changeover this month. As soon as the first call of the day came in, they all self-corrected. So, for landlines at least, and as I suspected, no time signal is sent other than the one attached to the CID data between the 1st & 2nd rings of every phone call. Presumably, if I never received new calls for days after the changeover, the time display being locally powered, might drift, and would be uncorrected for DST or Non-DST.
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