Procedure

     ISO2UTC ( Convert ISO time strings to UTC strings. )

     SUBROUTINE ISO2UTC ( TSTRNG, UTCSTR, ERROR )

Abstract

     Deprecated: This routine is deprecated because all high-level
     time conversion routines (STR2ET, UTC2ET, TPARSE) were updated
     to accept ISO formatted times on input.  This routine is 
     supported for purposes of backward compatibility only.

     Convert date-time strings represented in the format adopted by the
     International Standards Organization (ISO) to equivalent UTC time
     strings recognized by the SPICELIB routine TPARSE.

Required_Reading

     TIME

Keywords

     TIME

Declarations

     IMPLICIT NONE

     CHARACTER*(*)         TSTRNG
     CHARACTER*(*)         UTCSTR
     CHARACTER*(*)         ERROR

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     TSTRNG     I   String representing a calendar or julian date epoch
     UTCSTR     O   SPICELIB UTC string corresponding to TSTRNG
     ERROR      O   Error message if something went wrong.

Detailed_Input

     TSTRNG   is an input time string, containing a time string
              in ISO format. This routine is not sensitive to
              the case of the characters that make up TSTRNG.
              Thus 1992-192t12:29:28 and 1992-192T12:29:28
              are equivalent.

              The ISO standard time formats are:

                 Year Month Day    yyyy-mm-ddThh:mm:ss[.sss...]
                                   yyyy-mm-dd

                 Day of Year       yyyy-dddThh:mm:ss[.sss...]
                                   yyyy-ddd

              The letters y,m,d,h,m,s can stand for any digit.
              All digits are required in these formats. Moreover
              the year portion of these strings must be between
              1000 and 2999 inclusive.

              The length of TSTRNG should not exceed 80 characters.

              We point out that the format yyyy-ddd may be
              interpreted very differently by routine UTC2ET.
              1992-003 is interpreted by UTC2ET as March 1, 1992
              whereas it is interpret as January 3, 1992 by ISO2ET.

              User's should be aware of these differences in
              interpretation and exercise adequate care in their
              programs to avoid this possible confusion.

Detailed_Output

     UTCSTR   is the equivalent of TSTRNG, expressed in a UTC
              time string that can be parsed by the SPICELIB
              routine TPARSE.

Parameters

     None.

Exceptions

     1)  If the string is interpreted as an ISO format string and
         the year portion is not within the range [1000, 2999], the
         error SPICE(YEAROUTOFBOUNDS) is signaled. UTCSTR is
         not changed.

     2)  If the string does not clearly match the ISO format,
         the error SPICE(NOTISOFORMAT) is signaled. UTCSTR is not
         changed.

Files

     None.

Particulars

     The input string is converted to a UTC time string as defined
     by the SPICELIB routine TPARSE.

Examples

     To convert the time string 1992-04-03T14:12:28 to the
     corresponding ephemeris time, execute the following instructions:

        TSTRNG = '1992-04-03T14:12:28'

        CALL ISO2UTC ( TSTRNG, UTCSTR, ERROR )

        CALL TPARSE ( UTCSTR, UTCSEC, ERROR )

        CALL DELTET ( UTCSEC, 'UTC', DELTA )

        ET = DELTA + UTCSEC

Restrictions

     None.

Literature_References

     [1]  J. Jespersen and J. Fitz-Randolph, "From Sundials to Atomic
          Clocks, Understanding Time and Frequency," Dover
          Publications, Inc. New York, 1877.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     K.R. Gehringer     (JPL)
     J.M. Lynch         (JPL)
     B.V. Semenov       (JPL)
     E.D. Wright        (JPL)

Version

    SPICELIB Version 1.2.0, 23-DEC-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard. Remove obsolete
        reference to NAIF document 268 from $Literature_References.

    SPICELIB Version 1.1.2, 28-FEB-2008 (BVS)

        Corrected the contents of the $Required_Reading section.

    SPICELIB Version 1.1.1, 19-SEP-2006 (EDW)

        Added text to previously empty $Restrictions section.

    SPICELIB Version 1.0.0, 11-JUL-1995 (KRG) (JML)

        Based on

        EKLIB Version 1.1.0, 11-JUL-1995 (KRG)

           Fixed a typo in the $Detailed_Output section of the header.
           The output variable was listed as ET when it should have
           been UTCSTR.

           Changed the length of ASCII to be 100 rather than 128. This
           removes possible compiler warning messages for truncating
           character variables on assignments. The maximum nonblank
           length for an input time ISO string is 80 characters, so
           placing it into a temporary array of 100 characters should
           pose no difficulties.

        EKLIB Version 1.0.0, 25-FEB-1993 (JML)