Time becomes incorrect after a few weeks

sleep_legacy

Hi everyone, I have a problem with the time in my phone. I have set it one day through the "Set time automatically" button in Settings>System>Date & time. After a few weeks I realized that my time wasn't up to date (I was a few minutes "faster" than real time).
So I turned "Set time automatically" on again, the time turned right and I turned "Set time automatically" off.
After a few weeks my time was wrong again.

I don't want that my phone cheks the time all the time when I'm in WiFi so I don't want to activate "Set time automatically" permanently.
But its also not good that my time changes without me knowing it.

Can anyone help me or does anyone know what causes these issues?

treequell

Hi there, time updates are done on GrapheneOS in a more secure way than on stock Android. For more details, please see the following details from the FAQs. It's security sensitive to keep the time set accurately, and therefore it's recommended you enable the toggle to update the time automatically.

An HTTPS connection is made to https://time.grapheneos.org/generate_204 to update the time with a millisecond precision X-Time header. As part of future support for using other services, it falls back to the standard Date header with second precision.

This is a full replacement for Android's standard network time update implementation, which uses unauthentication SNTP (Simple Network Time Protocol) with fallback to the cellular network when it's not available (GNSS can also be used as a time source but is disabled by default, and OEMs can choose the priority order). Network time updates are security sensitive since certificate validation depends on having an accurate time, but the standard NTP / SNTP protocols used across most OSes have no authentication or encryption.

We plan to offer a toggle to use the standard functionality instead of HTTPS-based time updates in order to blend in with other devices.

Network time can be disabled with the toggle at Settings ➔ System ➔ Date & time ➔ Set time automatically. Unlike AOSP or the stock OS on the supported devices, GrapheneOS stops making network time connections when using network time is disabled rather than just not setting the clock based on it. The time zone is still obtained directly via the time zone provided by the mobile network (NITZ) when available which you can also disable by the "Set time zone automatically" toggle.

https://grapheneos.org/faq#:~:text=An%20HTTPS%20connection,NTP%20/%20SNTP%20protocols

sleep_legacy

treequell

I use my phone mostly in public WiFi and because of that I thought that it would be better to disable automatic time setting so the doesn't ask for the service all the time.

de0u

sleep_legacy I think the key issue is that phones generally are set up to correct time from some network source because they don't keep time very well on their own. So in practice your options may be accurate network-corrected time versus inaccurate time. Note that TOTP authenticators need fairly accurate time.

For the moment you could briefly enable network time a couple times per day on a trusted network.

r00xxbr

here the same problem , how fixed? i got the same problem a lot of people know got the same problem the hours is not sync normalli, also the option is ON but no work

GrapheneOS

It sounds like you may be blocking the network time connection with filtering such as DNS filtering.

Toiletterider

GrapheneOS which system app is responsible for keeping time?

de0u

Toiletterider As documented in "What kind of connections do the OS and bundled apps make by default?", periodic connections are made to https://time.grapheneos.org/generate_204.

Toiletterider

de0u thank you for the reply,
However the answer to my question is not in it...

Which system app is making the connection to sync time? It is not stated in the link.

de0u

Toiletterider Which system app is making the connection to sync time? It is not stated in the link.

It's not 100% clear that it works that way.

The explanation for the "Automatic date and time" toggle is "Set automatically using your network and wireless signals". So it is possible that one piece of code runs when the cellular network becomes connected and a different piece of code runs when a Wi-Fi network is connected. It is also possible that neither of those pieces of code is an "app" that shows up in Settings.

The HTTPS time client code appears to be in frameworks/base/core/java/android/net/HttpsTimeClient.java, and it appears that there is code in frameworks/base/core/java/android/util/NtpTrustedTime.java to force the HTTPS code to be used instead of the NTP code. The fact that those are framework classes does suggest that multiple bodies of code could invoke this code.

I've looked a bit and nothing is leaping out. Maybe I'll look more later, or maybe somebody else will chime in.

Meanwhile, can you confirm that the "Automatic date and time" toggle is on?

de0u

Toiletterider My hunch: SystemServer. If that's right, then the "Automatic date and time" toggle might be the only way for a user to enable/disable the network time client.