Xiaomi
Change Time Format auf Xiaomi
On Xiaomi phones running MIUI, the time format is not a separate choice by default. It is tied to the system language you have selected, so switching languages can silently switch the clock between 12-hour and 24-hour display.
This becomes a problem if you use your phone in one language but expect the time shown in a specific format, for example a 24-hour clock while the interface language defaults to 12-hour notation.
MIUI lets you break that link. Open Tap on Settings ➔ Tap on Additional settings ➔ Tap on Date & time ➔ Tap on Time format. From there, pick Choose 12-/24-houror Auto (based on system language) to either fix the format permanently or let MIUI keep following the system language.
Choosing 12-hour or 24-hour manually overrides the language-based behavior everywhere the clock appears: lock screen, status bar, and most apps that read the system time.
If you switch languages often and want the clock to always match the current language convention, leave the setting on Auto instead of forcing a fixed format.

