The month of October is Clergy Appreciation Month and dates back to 1992. Hallmark has a page giving details of this celebration. Here is some background from their site:
The mission of Clergy Appreciation Month is to uplift and encourage pastors, missionaries and religious workers by providing physical, emotional and spiritual support. There are more than 1 million full-time Christian ministry workers in the United States, including 350,000 senior pastors.
So make sure to thank your pastor, reverand, preacher and priest for all they do.