INTEGER FUNCTION ISDSTIME( JDATE ) INTEGER, INTENT(IN ) :: JDATE ! Julian date (YYYYDDD)
TRUEif and only if daylight savings time is in effect for the Julian date
JDATE, using the Zeller's-congruence algorithm to find the start and end for DST. Handles both pre-2007 (starts first Sunday in April, ends last Sunday in October) and 2007-and-after (second Sunday in March, first Sunday in November).
For Fortran-90 declarations and interface checking:
See also subroutines
DAYMON(),as well as EDSS/ Models-3 date-time manipulation programs
... USE M3UTILIO ... LOGICAL ISDSTIME INTEGER JDATE ... IF ( ISDSTIME( JDATE ) ) THEN !! ...daylight savings time in effect ... ELSE !! ...daylight savings time NOT in effect ... END IF ...
Up: Date-Time Manipulation Routines
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