How to get national holidays of selected country

I'm writing an app that allows the user to select a country from a list. When they pick a country, a list of national holidays of that country appears.

I've seen CalendarProvider and Google Calendar V3, but they seem to only provide the current user's calendar.

How can I get the national holidays of a specific country? Any suggestion would help me.

Update:

I've found this post which can get a list of holidays in JSON format. In this example, the country code is defined by calendar ID, for instance pt_br.brazilian#[email protected] or en.usa#[email protected].

But I can't find any documentation about this. Is it possible to use the API this way? If yes, where can I get those calendar IDs?

Problem solved by using Google Calendar API V3. The idea I found from this post. The holiday can get from default holiday calendar of google.

The ID list of default holiday calendar can be found here, support to 40 country.

A piece of code that handle permission and get holiday list:-

com.google.api.services.calendar.Calendar client = null;
        credential = GoogleAccountCredential.usingOAuth2(mContext, CalendarScopes.CALENDAR);
        credential.setSelectedAccountName(mList.get(0));
        client = getCalendarService(credential);
        do {
            com.google.api.services.calendar.model.Events events;
            events = client.events().list("en.usa#[email protected]").setPageToken(pageToken).execute();
            onHolidayChecked(events.getItems()); //result return here (events.getItems())
            pageToken = events.getNextPageToken();
        } while (pageToken != null);

private com.google.api.services.calendar.Calendar getCalendarService(GoogleAccountCredential credential) {
    return new com.google.api.services.calendar.Calendar.Builder(AndroidHttp.newCompatibleTransport(), new GsonFactory(), credential).build();
}

The CalendarProvider documentation states that it only provides the current user's calendar information.

The Calendar Provider is a repository for a user's calendar events. The Calendar Provider API allows you to perform query, insert, update, and delete operations on calendars, events, attendees, reminders, and so on.

You will need to access a third-party API (this one, for example) and load that information into your application.