Time­Cowan

Time

(current-millisecond)

Returns a rational number representing the current millisecond of the Posix epoch, which began on 00:00:00 on 1 January 1970, Coordinated Universal Time but excludes all leap seconds. Implementations SHOULD return a value that is as precise and accurate as possible. Implementations MAY return exact or inexact values, and SHOULD return inexact values unless:

• The value is an integer.
• The range of most-efficiently-implemented exact integers in the implementation exceeds the integer range of inexact rationals.

In practice this means that implementations with fixnums greater than 2⁵³ should return fixnums unless they have time-of-day clocks that provide more than 1 ms precision, and all other implementations should return IEEE 64-bit floats.

Advanced Time (WG2)

See TimeAdvancedCowan.

Time Durations and Periods (WG2)

See TimePeriodsCowan.