Is a jiffy an actual unit of time? As in "be there in a jiffy"?

A 'jiffy' in British English means much the same as 'moment'. No specific length of time constitutes a jiffy, so it could mean two minutes or two hours.

According to the New Hackers Dictionary a jiffy is 1.)the duration of one tick of the system clock on your computer (see tick). Often one AC cycle time (1/60 second in the U.S. and Canada, 1/50 most other places), but more recently 1/100 sec has become common. 'The swapper runs every 6 jiffies' means that the virtual memory management routine is executed once for every 6 ticks of the clock, or about ten times a second. 2.) Confusingly, the term is sometimes also used for a 1-millisecond wall time interval. Even more confusingly, physicists semi-jokingly use %60jiffy' to mean the time required for light to travel one foot in a vacuum, which turns out to be close to one nanosecond. 3.) Indeterminate time from a few seconds to forever. 'I'll do it in a jiffy' means certainly not now and possibly never. This is a bit contrary to the more widespread use of the word. - www.instinct.org/texts/jargon-file/jargon_25.html

A jiffy is an actual measurement of time. It is 1/100 of a second.

Depends on who is saying it. I have a sister who runs in three speeds...slow, slower and stop. Her "in a jiffies" last approximately 10 years.

However, to a normal person a "jiffy" is a "moment" or is the time it takes light to traverse the distance of 1 centimeter (33.3 pico seconds = 0.000,000,000,033,300 seconds).
1 light - cm is pretty quick!

The duration of one tick of the computer's system clock. Often one AC cycle time (1/60 second in the US and Canada, 1/50 most other places), but more recently 1/100 sec has become common.

Confusingly, the term is sometimes also used for a 1-millisecond wall time interval. Even more confusingly, physicists semi-jokingly use "jiffy" to mean the time required for light to travel one foot in a vacuum, which turns out to be close to one *nanosecond*.


a very short time (as the time it takes the eye blink or the heart to beat); "if I had the chance I'd do it in a flash"
http://dictionary.reference.com/search?q=jiffy

Informally, it is just an unspecified short period of time. However, different disciplines over time have defined specific time intervals for the term.

In electronics, the term means 1/60 or 1/50 of a second.

In computing, it is not an exact measure of time, but it is used to describe one tick of the system timer interrupt. Alternatively, it could be 1/250 of a second.

In physics, a jiffy is the time taken for light to travel to a specified distance, or the time it takes for light to travel one fermi making a jiffy 3 x 10 (to the -29th power)seconds.

The term "jiffy" is sometimes used in computer animation as a method of defining playback rate, with the delay interval between individual frames specified in 1/100th-of-a-second (10 ms) jiffies.

https://en.wikipedia.org/wiki/Jiffy_(time)

In electronics, a jiffy is the time between alternating current power cycles (1/60 or 1/50 of a second) — see alternating current.

https://en.wikipedia.org/wiki/Jiffy_(time)

1/100 second is commonly cited, but 1/50 and 1/60 are used as well.

http://www.dictionary.com/browse/jiffy

jiffy: n.
1. The duration of one tick of the system clock on your computer (see tick). Often one AC cycle time (1/60 second in the U.S. and Canada, 1/50 most other places), but more recently 1/100 sec has become common. “The swapper runs every 6 jiffies” means that the virtual memory management routine is executed once for every 6 ticks of the clock, or about ten times a second.

2. Confusingly, the term is sometimes also used for a 1-millisecond wall time interval.

3. Even more confusingly, physicists semi-jokingly use ‘jiffy’ to mean the time required for light to travel one foot in a vacuum, which turns out to be close to one nanosecond. Other physicists use the term for the quantum-nechanical lower bound on meaningful time lengths,

4. Indeterminate time from a few seconds to forever. “I'll do it in a jiffy” means certainly not now and possibly never. This is a bit contrary to the more widespread use of the word.

http://catb.org/~esr/jargon/html/J/jiffy.html