Image via Wikipedia"hot season of the year," O.E. sumor, from P.Gmc. *sumur- (cf. O.S., O.N., O.H.G. sumar, O.Fris. sumur, M.Du. somer, Du. zomer, Ger. Sommer), from PIE base *sem- (cf. Skt. sama "season, half-year," Avestan hama "in summer," Armenian amarn "summer," O.Ir. sam, O.Welsh ham, Welsh haf "summer"). O.N. sumarsdag, first day of summer, was the Thursday that fell between April 9 and 15. For Indian summer see India. The verb meaning "to pass the summer" is recorded from c.1440. Summer camp is attested from 1893; summer resort is from 1832; summer school first recorded 1860; theatrical summer stock id attested from 1942. Summertime is recorded from 1377; in Britain, as two words, with ref. to what in U.S. is "daylight saving time," it is recorded from 1916.