OnePlus
Change the Start of the Week in the Calendar App auf OnePlus
The OnePlus Calendar app sets its first day of the week automatically, based on the region stored in your phone's language and location settings. In most cases that means Sunday or Monday, depending on where you set up the device.
This becomes a problem when you work across time zones or coordinate with a team that follows a different week convention. A calendar that starts on the wrong day makes weekly views harder to read at a glance, especially when planning around weekends.
Oxygenos includes a manual override for this setting, separate from your region format. You can switch between Saturday, Sunday and Monday as the first day, and the change applies immediately to every week view in the app.
To adjust it, open Calendar ➔ Open the menu ➔ Settings ➔ General ➔ Start of the week, then pick the day that fits your schedule.
If the calendar still shows the wrong start day after changing this setting, check whether you are using a synced calendar account, like Google, that applies its own week-start preference on top of the local app setting.