# 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:** 2
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [August 22, 2025, 9:17am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/21 "2025-08-22T09:17:39Z")
The OP is the very definition of a solution looking for a problem. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [August 22, 2025, 10:57am UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/22 "2025-08-22T10:57:27Z")
> [@markn\_1](#): > > 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. Because the earth is spinning just barely faster. ---
**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 22, 2025, 1:30pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/23 "2025-08-22T13:30:21Z")
Stupid Moon trying to ruin our life. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [August 22, 2025, 1:31pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/24 "2025-08-22T13:31:47Z")
> [@Timz](#): > > Think it makes more sense to show the rounded-to-the-nearest-minute time > [@Chronos](#): > > But the convention is that clocks truncate time, rather than rounding it I think this is an important issue, and thank the OP. However, as Chronos points out, there is a well established convention. Similarly, we truncate time (or date) when we state our age, and consider it incorrect to round up when we are less than 6 months from our next birthday. Timekeeping is cool. I used to do complicated industrial experiments with multiple data acquisition systems and needed subsecond accuracy when matching subsystems. It galls me that I can’t tell my iPhone to always include seconds when displaying timestamps. ---
**Author:** ![Zoobi](https://avatars.discourse-cdn.com/v4/letter/z/13edae/32.png) [@Zoobi](https://boards.straightdope.com/u/Zoobi)\ **Post date:** [August 22, 2025, 2:01pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/25 "2025-08-22T14:01:29Z")
> [@Timz](#): > > It wasn’t when I last checked it a couple weeks ago. I doubt it ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [August 22, 2025, 2:19pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/26 "2025-08-22T14:19:42Z")
The tidal drag of the moon slowing the earth’s rotation, while the dominant force over the very long term, is not actually the most significant force modifying the earth’s speed of rotation over shorter time frames. That stronger force is redistribution of earth’s mass to or from the poles and equator combined with conservation of angular momentum. For example, during a glaciation period, sea levels drop and that water is frozen at high latitudes, which are closer to the axis of rotation, resulting in faster rotation and shorter days. Then the glaciers melt, and the opposite happens. And then after the glaciers have melted, you have the isostatic rebound of the earth’s crust which changes the mass distribution again. We are still in an isostatic rebound phase, and we’re also melting the polar ice caps, both of which have more impact on the length of days year-to-year than tidal friction. ---
**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 22, 2025, 3:34pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/27 "2025-08-22T15:34:38Z")
Stupid Earth trying to ruin our life. ---
**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 22, 2025, 3:57pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/28 "2025-08-22T15:57:14Z")
There is even a measurable effect caused by human activity. Dams that sequester large bodies of water can redistribute enough mass to change the speed of Earth’s rotation. ---
**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 22, 2025, 3:57pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/29 "2025-08-22T15:57:15Z")
ETA @Saint_Cad Yeah. But we’ll show it! Here Earth, take another 5C of warming! See how you like that!,!? BWAAA HAA HAAA! ---
**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 22, 2025, 4:01pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/30 "2025-08-22T16:01:35Z")
That’s actually brilliant. As it gets warmer Earth gets less dense by conservation of momentum it speeds up thus canceling out the slowing. ---
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 22, 2025, 6:16pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/31 "2025-08-22T18:16:02Z")
Well well well – we can’t trust [time.gov](http://time.gov). I just tried it again, and the display now changes a noticeable fraction of a second early – dunno if it’s a full half-second. What’s the easy way to compare them, sound against screen? (I.e., screen display against 303-499-7111, which presumably has the correct UTC.) ---
**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, 6:23pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/32 "2025-08-22T18:23:25Z")
🤯 you’re scaring me now. My nap is ruined. Thanks universe. 😬 ---
**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 22, 2025, 6:44pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/33 "2025-08-22T18:44:36Z")
You’re on a dead end errand. The random delays in the phone system cannot be controlled for. The random delays on the internet can be controlled for to a smaller (but still non-zero) error delta than a human can perceive. [Time.gov](http://Time.gov) is right enough for any real purpose you might have. All other time sources are more wrong than it is. Nothing more can usefully be said unless you want to start buying serious expensive gear or paying for way upstream access. Metrology is a very deep subject; we have a retired metrologist here somewhere; shame I forget his handle. And of all the fundamental standards, time is one of the harder ones. ---
**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 22, 2025, 7:00pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/34 "2025-08-22T19:00:32Z")
> [@LSLGuy](#): > > And of all the fundamental standards, time is one of the harder ones. “Time is an illusion. Lunchtime doubly so.” — Douglas Adams Stranger ---
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 22, 2025, 7:05pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/35 "2025-08-22T19:05:13Z")
So you figure 303-499-7111 isn’t reliable – but probably WWV on the shortwave is? (10 MHz most likely; 5 MHz if 10 MHz doesn’t come in well.) I don’t have a shortwave radio any more – I’d be curious to see how unreliable the phone is. ---
**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 22, 2025, 7:09pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/36 "2025-08-22T19:09:26Z")
Compare the phone to [time.gov](http://time.gov). Done. You do you, but IMO all else is mental masturbation to no actual useful knowledge. ---
**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 22, 2025, 7:11pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/37 "2025-08-22T19:11:59Z")
The [NTP protocol](https://en.wikipedia.org/wiki/Network_Time_Protocol) uses a clever algorithm to factor out network delays, so the client gets a time that is accurate to much less than the network delay. However, it depends on the delay being consistent during the NTP request (client-to-server) and the response (server-to-client). In an environment with asymmetric delays or delays that vary over time, even NTP won’t deliver accurate results. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [August 22, 2025, 7:27pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/38 "2025-08-22T19:27:30Z")
> [@Saint\_Cad](#): > > Stupid Moon trying to ruin our life. [Let’s blow it up!](https://www.youtube.com/watch?v=GTJ3LIA5LmA) ---
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 23, 2025, 5:59pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/39 "2025-08-23T17:59:02Z")
> [@LSLGuy](#): > > [Time.gov](http://Time.gov) is right enough for any real purpose you might have. Meaning, being off by a half-second won’t bother anyone? If you’re at latitude 38 North, the sun’s azimuth at noon changes by about 10 arc seconds in a half second of time (less in December, more in March/September). So if you’re determining true north, and you want to do it in the daytime, guess you’re stuck with shortwave WWV. ---
**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 23, 2025, 8:04pm UTC](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342/40 "2025-08-23T20:04:04Z")
Doesn’t bother me in the least. The only thing that’s perfect is imperfection. [Previous page](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342.md?page=1) [Next page](https://boards.straightdope.com/t/cell-phone-time-which-way-makes-more-sense/1022342.md?page=3)