Please tap "Display settings" from the setting screen and turn off the checkmark of the calendar written as birthday or Contact, etc. This will no longer be displayed on the calendar.
■ If you want to hide birthdays from your Google Calendar account
To turn off the birthdays that appear in the calendars under your Google Calendar account, follow these steps:
1. Open the"Google Calendar" app.
2. From the [Settings] menu, select [Birthdays].
3. Turn off the checkbox for [Sync from Contacts].
After confirming that birthdays are no longer shown in the Google Calendar app, they will also disappear in this calendar app. Because of sync delays, it may take some time for the changes to take effect. If birthdays are still visible, please try restarting your device.
The birthdays should now be hidden.
Thank you.