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DOUBLE PRECISION FUNCTION sla_DTT (UTC)
*+
* - - - -
* D T T
* - - - -
*
* Increment to be applied to Coordinated Universal Time UTC to give
* Terrestrial Time TT (formerly Ephemeris Time ET)
*
* (double precision)
*
* Given:
* UTC d UTC date as a modified JD (JD-2400000.5)
*
* Result: TT-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 only be guaranteed up to the end of the second 23:59:59.
*
* 2 Pre 1972 January 1 a fixed value of 10 + ET-TAI is returned.
*
* 3 See also the routine sla_DT, which roughly estimates ET-UT for
* historical epochs.
*
* Called: sla_DAT
*
* P.T.Wallace Starlink 6 December 1994
*
* Copyright (C) 1995 Rutherford Appleton Laboratory
*-
IMPLICIT NONE
DOUBLE PRECISION UTC
DOUBLE PRECISION sla_DAT
sla_DTT=32.184D0+sla_DAT(UTC)
END
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