The public holiday will be automatically populated following the address of the company. At the moment, only Malaysia, Singapore and Taiwan public holiday will be automatically updated and it is following the country and state holiday.
In Swingvy settings, you can check the holiday from the:
Step 1 - Go to HR hub
Step 2 - Click on Settings
Step 3 - Click on Company settings
Step 4 - Select Office
Step 5 - Click on Holiday
All holiday can be turned on/off according to your company policy. You can also add a holiday and it will be reflected in the company calendar.