# Cell-phone time: which way makes more sense? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 20, 2025, 9:58pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342 "2025-08-20T21:58:59Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 20, 2025, 9:58pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/1 "2025-08-20T21:58:59Z")
Offhand guess: most? all? cell phones are supposed to change their displayed time from 11:59 to 12:00 at 12:00:00. Think it makes more sense to show the rounded-to-the-nearest-minute time, changing to 12:00 at 11:59:30? ( [Time.gov](http://Time.gov) shows the time to the second, and apparently they do round it – it switches to 12:00:00 a half-second “early”.) ---
**Author:** ![Eyebrows\_0f\_Doom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eyebrows_0f_doom/32/3119_2.png) [@Eyebrows\_0f\_Doom](https://boards.straightdope.com/u/Eyebrows_0f_Doom)\ **Post date:** [August 20, 2025, 10:04pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/2 "2025-08-20T22:04:06Z")
Huh? Why would a clock not show the actual time? It changes to 12 at 12. Not before. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [August 20, 2025, 10:07pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/3 "2025-08-20T22:07:40Z")
That’s just absurd. I don’t want the estimated time. I want the actual time ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 20, 2025, 10:16pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/4 "2025-08-20T22:16:54Z")
Well, the actual time is only 12:00 for an instant. If you’re only displaying hours and minutes, then most of the time, your clock won’t show the actual time. When the actual time is 12:00:30, it’s neither 12:00 nor 12:01. The question is just how you want it to be incorrect. But the convention is that clocks truncate time, rather than rounding it, and any departure from convention is likely to be more confusing than following it, regardless of whether the convention is logical or not. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [August 20, 2025, 10:21pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/5 "2025-08-20T22:21:11Z")
> [@Chronos](#): > > Well, the actual time is only 12:00 for an instant. If you’re only displaying hours and minutes, then most of the time, your clock won’t show the actual time. And because light can only travel from the display to your eyes at light speed you’ll never see the actual time! ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 20, 2025, 10:25pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/6 "2025-08-20T22:25:07Z")
> [@crowmanyclouds](#): > > And because light can only travel from the display to your eyes at light speed you’ll never see the actual time! There is also the problem of relativistic adjustments required for altitude and latitude corrections. Stranger ---
**Author:** ![Zoobi](https://avatars.discourse-cdn.com/v4/letter/z/13edae/32.png) [@Zoobi](https://boards.straightdope.com/u/Zoobi)\ **Post date:** [August 20, 2025, 10:30pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/7 "2025-08-20T22:30:40Z")
The proximity to high density objects will affect things as well. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 20, 2025, 10:55pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/8 "2025-08-20T22:55:30Z")
This is why all of my mechanical chronometers are not only _Antimagnetische_ but also _Antigravitische_. You can never be too careful about the chronometric effects of wandering quantum singularities, Stranger ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [August 20, 2025, 11:01pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/9 "2025-08-20T23:01:31Z")
I once built a very accurate clock but it immediately turned into a black hole. Foiled by Heisenberg. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [August 20, 2025, 11:12pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/10 "2025-08-20T23:12:03Z")
> [@Timz](#): > > shows the time to the second, and apparently they do round it – it switches to 12:00:00 a half-second “early”. It’s bad form to round a already rounded number 14.59 rounded to the nearest digit is 15, rounded then again to the nearest 10’s is 20, though it should have been rounded to 10, the spacecraft then misses mars and ends up crashing onto some poor souls home in Uganda. Moral of the story, don’t re-reround that was rounded for you. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [August 20, 2025, 11:22pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/11 "2025-08-20T23:22:52Z")
If it’s late enough in the day, should it round the date to tomorrow’s date? ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [August 20, 2025, 11:36pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/12 "2025-08-20T23:36:44Z")
Happy new year 2026 ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 20, 2025, 11:47pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/13 "2025-08-20T23:47:04Z")
I always round to the nearest irrational number. Stranger ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 21, 2025, 12:27am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/14 "2025-08-21T00:27:37Z")
Why not? That’s the way the Jewish calendar works. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 21, 2025, 3:25am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/15 "2025-08-21T03:25:51Z")
> [@Timz](#): > > ( [Time.gov](http://Time.gov) shows the time to the second, and apparently they do round it – it switches to 12:00:00 a half-second “early”.) I find this unlikely. Do you have a real cite, or is this your own conclusion? ---
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 21, 2025, 5:25pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/16 "2025-08-21T17:25:28Z")
As a matter of fact, [Time.gov](http://Time.gov) does seem to be changing on the second now. It wasn’t when I last checked it a couple weeks ago. The way you check is to dial 303-499-7111 and listen, while watching the display change at [Time.gov](http://Time.gov). Each UTC minute is supposed to start within 0.05 second of the start of the 0.8-second tone. (WWV also gives the current estimate of the difference between UT1 (Earth time) and UTC. That’s what the double click at second number 1 means, at the moment – best guess is UT1 is 0.1 second later than UTC. So no need for a leap second this year.) ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [August 21, 2025, 6:04pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/17 "2025-08-21T18:04:02Z")
It was decided in 2022 to abandon leap seconds by 2035 at the latest. I don’t know if there will be any leap seconds between now and 2035, but I hope not. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [August 21, 2025, 8:27pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/18 "2025-08-21T20:27:37Z")
That phone/time concept may work for some people. In [this thread](https://boards.straightdope.com/t/why-are-you-always-late/942631) we learn that 12 noon may mean anything from 12:10pm to somewhere around 3 for some people. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 22, 2025, 7:55am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/19 "2025-08-22T07:55:59Z")
I wonder if this idea is more appealing to the set of people who believe setting all their clocks 5 minutes fast will stop them being perennially late. I want to know the time. Not _what the time is going to be_ ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [August 22, 2025, 8:21am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/20 "2025-08-22T08:21:50Z")
No no no, you’re screwing up my day. Noon is when I have my lunch. 12:10 is when I nap. I may sleep to 3, but no matter that. My personal time continuum can’t take anymore stress. What day is it, btw? 😊 (Oh, crap.i forgot all my clocks are 5-10 minutes early. I’m not sure which ones are which anymore. Have we had DST lately?) [Next page](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342.md?page=2)