@userCsyxqluHlP The holidays you see in Samsung calendar are from the calendars enabled in your Google account.
To select the holidays you want:
- Visit https://calendar.google.com/.
- On the lower left, click the + at the end of "Other calendars".
- Choose "Browse calendars of interest"
- Under "Global religious holidays", enable the ones that you are interested in.
- Now Open the Samsung Calendar app
- Click the 3 line menu in the upper left corner.
- Find your Google email account and click the downward arrow at the right end to see all the calendars associated with that account.
- Enable the calendars that you want to see.