A year is not a number of working days. It is one number in Germany and a different one in India, and it changes again if your week is not Monday to Friday. Pick a jurisdiction and a year and we will show every month, with the closures that shortened it named.
Counted from the same corpus the API serves, so this page and an API answer for the same jurisdiction cannot disagree. Public holidays only — company shutdowns, school terms and local half-days are not in it, and a closure that falls on a day your week already excludes costs you nothing.
Count between two dates Add working days to a date Find the long weekends