How «One o’clock jump» got its name

(Source: NPR Music articles)
«One O’Clock Jump» originally had a different title. Co-arranger Eddie Durham called it «Blue Ball»(ph) but the musicians in the band referred to the tune with a more scatological variation. When the band began performing at Kansas City’s Reno Club in 1935 where their set was broadcast by a local radio station, the title became a problem, says historian Phil Schapp.
» The radio announcer, confronted with what Count Basie said, `We’re going to play «Blue Ball,»‘ says, `I don’t know about that. I don’t think I can say that on the air.’ And because of the air time connection being near 1:00 in the morning, they called it the ‘One O’Clock Jump.'»