OnePlus
Set the Time Manually auf OnePlus
Oxygenos syncs the clock automatically as soon as the phone picks up a signal from your mobile network or Wi-Fi provider. This keeps the time accurate for most people, but it also means any manual adjustment gets overwritten within seconds because the network source still takes priority.
To take control of the clock yourself, disable that automatic sync first. Go to Open the Settings ➔ Tap on System ➔ Tap on Date & time and turn off Disable Use network-provided time. Once network time is off, tap Tap on Time, enter the value you need and confirm with Set the time and tap OK.
Setting the time manually makes sense when you travel across time zones and want to keep a reference clock, when you test apps that depend on a specific timestamp, or when your carrier is delivering an incorrect time because of a local network issue.
Keep in mind that disabling network time usually affects the date field too, so check that value if it looks off. If your phone connects to different networks regularly, switch automatic time back on afterward to avoid drift.