[78-L] 12 O'Clock Jump...?!

[Steven C. Barr]

Listening to a blues CD I picked up (from 1993!)...and one of the tunes
thereon is an instrumental version of the above title...?! Was this a swing-
era original? I know of "One O'Clock Jump" (and indeed often quote
its "riff" on harmonica...!)...but was 12 O'Clock also used in a different
"Jump"-titled number? Or did the band decide to "reset the clock" in a
tune of their own?!

...stevenc