Convert day to femtosecond

day

Definition: A day (symbol: d) is an accepted, non-SI unit of time that is defined based on the SI (International System of Units) unit of time, the second, and is equal to 86,400 seconds.

History/origin: The term "day" originates from the Old English term "dæg." It is approximately equal to the period required for the Earth to complete a full rotation with respect to the sun. This was later re-defined in terms of the second in 1960, when the second was redefined in terms of Earth's orbital motion in the year 1900. The second, and therefore the day, was again re-defined in 1967 by atomic electron transition.

Current use: The day is a term used worldwide within many contexts one of the most common of which is to refer to a time interval of 24 hours. It is also used to reference daytime, or the period of time during which the sun is above the horizon. The term also has other colloquial uses such as the day of the week and fixed clock periods like 6:00 am to 6:00 pm, among others.

femtosecond

Definition: Femtosecond is a measure of time duration. For conversion purposes, its value is 1.0e-15 times the reference unit, second.