Subscribe multiple holiday calendar from official iCloud

Introduction

In the Apple iCloud system, a holiday calendar is subscribed automatically depends your Region setting. Only one holiday calendar can be displayed at the same time. To subscribe more holiday calendars through the official iCloud system, we can add the calendar manually from the icloud website.

Method

Type the link https://p20-calendars.icloud.com/holidays/AA_BB.ics in safari will auto-subscribe the holiday’s calendar into your iCloud calendar.

Modify the filename located at the end of the web-link to subscribe to the holiday calendar in different countries. The filename must be in AA_BB.ics format which AA is the country code and BB is the language code.

Here are the examples of holiday calendar in different countries:

# Hong Kong holiday in Cantonese
https://p20-calendars.icloud.com/holidays/hk_zh.ics

# Hong Kong holiday in English
https://p20-calendars.icloud.com/holidays/hk_en.ics

# British holidays
https://p20-calendars.icloud.com/holidays/gb_en.ics


# United States holiday 
https://p20-calendars.icloud.com/holidays/us_en.ics

Reference:

How to add additional calendar (holidays) to iPhone? from ios