SLA_DAT - TAI-UTC   

ACTION:

Increment to be applied to Coordinated Universal Time UTC to give International Atomic Time TAI.

CALL:

D = sla_DAT (UTC)

GIVEN:

UTC UTC date as a modified JD (JD-2400000.5)

RETURNED:

sla_DAT TAI-UTC in seconds

NOTES:

1.

The UTC is specified to be a date rather than a time to indicate that care needs to be taken not to specify an instant which lies within a leap second. Though in most cases UTC can include the fractional part, correct behaviour on the day of a leap second can be guaranteed only up to the end of the second $23^{\rm h}\,59^{\rm m}\,59^{\rm s}$.

2.

UTC began at 1960 January 1. To specify a UTC prior to this date would be meaningless; in such cases the parameters for the year 1960 are used by default.

3.

This routine has to be updated on each occasion that a leap second is announced, and programs using it relinked. Refer to the program source code for information on when the most recent leap second was added.