Oppo
Set an Alternate Calendar for Dates auf Oppo
The alternate calendar feature lets you display a second date system next to the standard Gregorian calendar on your Oppo phone. This is useful for tracking Chinese, Hebrew, or Hijri dates without switching apps.
The option only appears if Google Calendar is installed. If you cannot find the setting described below, install Google Calendar first and restart the Calendar app.
To activate it, go to Tap on Calendar ➔ Open the Menu ➔ Tap on Settings ➔ Tap on General ➔ Tap on Alternate calendar ➔ Choose an Option.
Available options typically include the Chinese calendar, Simplified Chinese calendar, Traditional Hebrew calendar, Hijri calendar, and Civil Hijri calendar. Pick the one you need and the app adds it as a secondary date reference in day and month views.
If dates still look wrong after switching, double check your region and language settings, since some alternate calendars depend on the system locale.