Holiday Calendar for Ukraine is empty

I'm not sure if this is a right place to ask, but since calendars are on Thunderbird page I guess it is. I downloaded a calendar from https://www.thunderbird.net/uk/calendar/holidays/ for Ukraine (direct link -- https://www.thunderbird.net/media/caldata/autogen/UkraineHolidays.ics) and it doesn't contain any holiday. I did that from my Nextcloud server and directly from browser -- both times result is the same.