Add German holidays to your calendar
A subscription is a link your calendar reloads regularly. The holidays show up as a separate calendar you can show or hide. Your own events are not touched.
Google Calendar
The "Google Calendar" button opens Google with the subscription ready; you only confirm. By hand, in a browser: click + next to "Other calendars", choose "From URL" and paste the copied link. On Android, the calendar appears after the next sync; if not, switch it on in the app's settings.
Outlook
"Outlook.com" and "Microsoft 365" open Outlook on the web with "Subscribe from web" filled in. In new Outlook for Windows it works the same via "Add calendar". In classic Outlook: Home → Add Calendar → From Internet, then paste the link.
Apple Calendar (iPhone, iPad, Mac)
The "Apple Calendar" button opens the subscription directly; confirm with "Subscribe". By hand on iPhone: Settings → Apps → Calendar → Calendar Accounts → Add Account → Other → Add Subscribed Calendar, then paste the link.
Hide the built-in holidays
Google and Apple ship their own holiday calendars, which don't reliably tell the states apart. To avoid duplicates, untick "Holidays in Germany" under "Other calendars" in Google, or deselect the holiday calendar under "Calendars" in Apple Calendar.
Holidays in your team or work calendar
A subscription only shows the holidays to you. If they should appear as real events in another calendar, for example the Outlook calendar colleagues use for scheduling, Kalender Sync can mirror a subscription into Google, Outlook or iCloud, starting with the Basic plan.