Why doesn't the oppo mobile phone calendar display the date?

Calendar Personalization ColorOS 6 and above: Open Calendar Application Click the ":"icon in the upper right corner to personalize the calendar. 1, week start date: choose one day from Monday to Sunday as the start date. 2. Display legal holidays: select whether to display legal holidays. 3. Display contact's birthday: select whether to display the contact's birthday. 4. Display China Gregorian calendar: select whether to display China Gregorian calendar. 5. Display holiday information: after opening, display holiday information in the schedule area. 6. Import the timetable determined by Breeno: including train tickets, movie tickets, hotels, credit cards, loan bills, etc. , can be opened or closed separately. 7. Import a schedule file: You can import a schedule file into a calendar. 8. Personalized reminder time: Click the default reminder time to set the whole day schedule, arrangement and reminder time for birthday/anniversary/countdown day. 9. Set time zone: After the time zone priority option is turned on, you can set the time zone yourself. When turned on, the scheduled date and time are always displayed in the selected time zone first. If off, the time will be displayed according to the current time zone. This answer applies to all OPPO models.