Set the NTP server of your android device

android-set-ntp-server.md

tags	Android Android Things

Set the NTP server of your android device

Just use this command to set a server address to automatically sync your device time. ( ͡° ͜ʖ ͡°)✧

$ adb shell settings put global ntp_server <new-ntp-server>

Background

I have a Raspberry Pi 3 with Android Things installed on it. But the time is never synchronized...

After googling it, I found this piece of code in NtpTrustedTime.java

public class NtpTrustedTime implements TrustedTime {
    ...
    public static synchronized NtpTrustedTime getInstance(Context context) {
        if (sSingleton == null) {
            final Resources res = context.getResources();
            final ContentResolver resolver = context.getContentResolver();
            final String defaultServer = res.getString(
                    com.android.internal.R.string.config_ntpServer);
            final long defaultTimeout = res.getInteger(
                    com.android.internal.R.integer.config_ntpTimeout);
            final String secureServer = Settings.Global.getString(
                    resolver, Settings.Global.NTP_SERVER);
            final long timeout = Settings.Global.getLong(
                    resolver, Settings.Global.NTP_TIMEOUT, defaultTimeout);
            final String server = secureServer != null ? secureServer : defaultServer;
            sSingleton = new NtpTrustedTime(server, timeout);
            sContext = context;
        }
        return sSingleton;
    }
}

It shows that android tring to get NTP server from:

1. Settings.Global.NTP_SERVER first

2. Then com.android.internal.R.string.config_ntpServer

And the NTP server of my Android Things is time.android.com, that's why it dose not work (I'm in China...).

---

Fortunately, it is easy to set settings via adb:

$ adb shell settings put global ntp_server asia.pool.ntp.org

# test
$ adb shell settings get global ntp_server 
> asia.pool.ntp.org

🎉 CHEERS

Thank you for this thread.

There is no existing ntp_server setting in LineageOS 20 but can easily be created just by pushing the "put global ntp_server domain" command through adb.

Setting is preserved between reboots and my router logs can confirm that NTP address changed from time.android.com to the chosen NTP server. GPS automatically connects to time.xtracloud.net (Cloudflare) in this ROM.

Failed to execute this command, my devices is android 12 colorOS, it seems no write permisson

➜ /Users/guaio >adb shell settings put global ntp_server ntp.aliyun.com

Exception occurred while executing 'put':
java.lang.SecurityException: Permission denial: writing to settings requires:android.permission.WRITE_SECURE_SETTINGS
	at com.android.providers.settings.SettingsProvider.enforceWritePermission(SettingsProvider.java:2640)
	at com.android.providers.settings.SettingsProvider.mutateGlobalSetting(SettingsProvider.java:1632)
	at com.android.providers.settings.SettingsProvider.insertGlobalSetting(SettingsProvider.java:1586)
	at com.android.providers.settings.SettingsProvider.call(SettingsProvider.java:588)
	at android.content.ContentProvider.call(ContentProvider.java:2473)
	at android.content.ContentProvider$Transport.call(ContentProvider.java:521)
	at com.android.providers.settings.SettingsService$MyShellCommand.putForUser(SettingsService.java:382)
	at com.android.providers.settings.SettingsService$MyShellCommand.onCommand(SettingsService.java:278)
	at com.android.modules.utils.BasicShellCommandHandler.exec(BasicShellCommandHandler.java:97)
	at android.os.ShellCommand.exec(ShellCommand.java:38)
	at com.android.providers.settings.SettingsService.onShellCommand(SettingsService.java:50)
	at android.os.Binder.shellCommand(Binder.java:970)
	at android.os.Binder.onTransact(Binder.java:854)
	at android.os.Binder.execTransactInternal(Binder.java:1226)
	at android.os.Binder.execTransact(Binder.java:1163)

Thanks for the information. I've tried several servers, cn.ntp.org.cn is the fastest one in China.

In my device if I first of all do adb shell settings get global ntp_server, it returns null.

For those trying to connect to your TV, I used adb connect 192.168.1.65:5555 to connect to my tv via LAN. Once you run that command you're gonna have to click Accept on the pop-up that is shown on your tv screen.
adb devices should show your TV as active, then you can run the commands above.

I ended up enabling the ntp server on my OpenWRT router and let time.android.com resolve to the router. Worked immediately.

How to sync device time from ntp server immediately?

I find this command in Android offical docs: cmd network_time_update_service force_refresh in ADB Shell
https://source.android.com/docs/core/connect/time/network-time-detection#interacting-network-time-update-service

How to sync device time from ntp server immediately?

I find this command in Android offical docs: cmd network_time_update_service force_refresh in ADB Shell https://source.android.com/docs/core/connect/time/network-time-detection#interacting-network-time-update-service

Thank you 1 year later! Hello from google

Android 14 & higher natively support multiple NTP servers for redundancy.

I figured out how to put multiple NTP servers onto ntp_server after looking at NtpTrustedTime for like a day.
$ adb shell settings put global ntp_server "ntp://time.google.com'|'ntp://time.cloudflare.com'|'ntp://pool.ntp.org"

It is explained inside the documentation on how each server is separated however command line also uses the pipe character for commands so you have put it inside quote marks like this '|'

You can verify if your device support multiple NTP server using
$ adb shell cmd network_time_update_service force_refresh
&
$ adb shell cmd network_time_update_service dump