afternooner
/ˌɑːftəˈnuːnə/ /ˌaftəˈnuːnə/noun
A person who spends an afternoon engaged in a certain activity, or at leisure. Frequently with the relevant day specified, as Saturday afternooner, Sunday afternooner, etc.
Origin
Late 19th century; earliest use found in Augustus J. C. Hare (1834–1903), author. From afternoon + -er.