Time Quantity and Units

Time is a SI base quantity. Definitions are provided in namespace time. The base quantity defines derived quantity types SecondClass, IntSecondClass, LongSecondClass, and MinuteClass, and Variables Time, IntTime, LongTime, and MinuteTime, as well as Constant TimeConstant and VariableVector TimeVector.

The Dimension of Time is $(0, 0, 1, 0, 0, 0, 0)$ .

Time defines the following Units:

Second (prefixable)
Minute
Hour
Day
Year
Svedberg
Atomic

The default unit is second (s). The default name in the base quantity is `time', and the default symbol is `t'. The derived quantities do not overwrite these values.

The proposed recommendations of IUPAC and IUGS [Holden/deBievre/etal_2009] that differences of times (duration) should be given in the usual time units rather than specific (ad hoc) units is naturally followed when using the objects provided.

In order to resolve ambiguities, it might be necessary to further qualify names from namespace time. Thus,it might be necessary to write quantity::time::Second to avoid compiler error messages.

[Holden/deBievre/etal_2009] N.E. Holden, P. De Bi\'evre, P.R. Renne, and I.M. Villa, Convention on the Use of Units for Time in Earth and Planetary Sciences (IUPAC-IUGS Recommendations 200X) (pre-print)

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