I can answer for my pastor (we’re a General Baptist sort of church with four full-time employees). About a day a week goes to writing and preparing for sermons. Several appointments per day (maybe 50% of his time total) goes to church members who have concerns that range from religious topics, prayer for unemployment or disease, even simple marriage and substance abuse counseling. When my mother-in law was dying three years ago, he spent four hours talking to her (and on Thanksgiving nonetheless).
So that’s accounted for something like 70% of his time right there. The rest is a lot of administrative stuff - church budgets, lease negotiations, strategy meetings, etc. It’s the same kind of stuff you’d expect any small business owner to be involved in.
Frankly, it’s about the worst possible job I could imagine having, and I’m just thankful God’s given it to someone other than me.