Google Calendar changed how holidays are displayed, and information other than public holidays now appears on Google Calendar.
You can show public holidays only by changing the following setting.
How to change the setting
- Open Google Calendar settings in a web browser, then click "Add calendar" > "Browse calendars of interest".
- Under "Regional holidays", click the dropdown next to your country's holiday calendar and select only "Public holidays" (deselect "Other observances").
If the change is not reflected
It may take some time for Google Calendar to reflect the change.
You can also consider using this app's built-in "Japanese holiday" data instead.
In "Display settings", turn off Google Calendar's holiday calendar to hide it, and then turn on "Japanese holiday" under "General" on the settings screen.
This way, only the Japanese national holidays are displayed.