[2] It was common in a number of Scots English dialects and in John Jamieson's Etymological Dictionary of the Scottish Language (1808) it is suggested that it is a corruption of 'gliff' (glimpse) or 'gliffin' (glance) [3] (compare: 'in the blink of an eye') and may ultimately derive from Gothic or Teutonic words for 'shine'.
[7] It is not an absolute time interval unit, since its duration depends on the clock interrupt frequency of the particular hardware platform.
[citation needed] Some 1980s 8-bit Commodore computers, such as the PET / VIC-20 / C64, had a jiffy of 1/60 second, which was not dependent on the mains AC or video vertical refresh rate.
[9] A timer in the computer creates the 60 Hz rate, causing an interrupt service routine to be executed every 1/60 second, incrementing a 24-bit jiffy counter, scanning the keyboard, and handling some other housekeeping.
In astrophysics and quantum physics a jiffy is, as defined by Edward R. Harrison,[13] the time it takes for light to travel one fermi, which is approximately the size of a nucleon.