Days to Shakes (d to shake)
1 day equals 8,640,000,000,000 shakes exactly.
How to convert days to shakes
To convert days to shakes, multiply the number of days by 8,640,000,000,000. This factor is exact. To go the other way, multiply shakes by 1.157407407×10⁻¹³ (rounded).
shakes = days × 8,640,000,000,000
Example: 10 days = 86,400,000,000,000 shakes.
Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.
About these units
Day (d)
24 hours or 86,400 seconds. The mean solar day; the actual rotation of the Earth is about 4 minutes shorter (see sidereal day).
Old English dæg is the root of our day, with close cousins in German Tag, Dutch dag and Icelandic dagur, all descending from Proto-Germanic dagaz. It is the oldest unit here, because the cycle of light and dark needs no instrument. Yet the day we count is a constructed average: the actual interval from one noon to the next varies through the year by up to about 7.9 seconds, because Earth's orbit is elliptical and its axis is tilted.
Astronomers smooth this out with a fictitious mean Sun, giving the mean solar day, and the day in the SI sense is fixed at exactly 86,400 seconds. Reality has drifted slightly: the mean solar day has recently averaged about 86,400.002 seconds, and tidal drag from the Moon is lengthening it by about 2 milliseconds per century. That is why 27 leap seconds were added to UTC between 1972 and 2022. One rotation measured against the distant stars is shorter, about 23 hours 56 minutes 4.09 seconds, and a year contains one more of these sidereal days than solar days.
1 day = 86,400 seconds (exactly).
Sources: Wikipedia: Day; BIPM: SI Brochure, 9th edition
Shake (shake)
Exactly 10 nanoseconds. Coined at the Manhattan Project for nuclear chain reactions, from the phrase 'two shakes of a lamb's tail'.
Physicists on the wartime Manhattan Project needed a handy name for an interval that kept turning up in their chain-reaction calculations, and they settled on the shake. It is defined as 10 nanoseconds, or 10 to the power of minus 8 second. The name plays on the English idiom about something happening in two shakes of a lamb's tail, meaning very quickly.
One step of a fission chain, in which a neutron causes a fission that releases more neutrons, takes roughly one shake, and a whole reaction is typically over within 50 to 100 shakes, according to Wikipedia. The shake was coined in the same circle and for similar reasons as the barn, a unit of cross-sectional area. It is an informal metric unit rather than an SI unit. A shake equals 10,000 picoseconds, and 100 million shakes make one second.
1 shake = 1×10⁻⁸ seconds (exactly).
Sources: Wikipedia: Shake (unit); Wikipedia: Picosecond
Related conversions
- Shakes to days (reverse)
- Days to seconds
- Days to minutes
- Days to hours
- Days to weeks
- Days to months
- Days to years
- Days to milliseconds
- Days to microseconds
- Days to nanoseconds
- Days to decades
- Days to centuries
- Days to millennia
- Seconds to shakes
- Minutes to shakes
- Hours to shakes
- Weeks to shakes
- Months to shakes
- Years to shakes
See all time units.