COMPUTE GAG_DATE

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COMPUTE GAG_DATE

            [SIC\]COMPUTE IntDate GAG_DATE "15-DEC-2035"
            [SIC\]COMPUTE StrDate GAG_DATE 4127

        GAG_DATE  keyword converts a string date into a "radio Julian date" (in-
        teger value), or vice-versa. The kind of the output variable (resp.  in-
        teger  or  character)  rules the expected kind for input variable (resp.
        character or integer). The output variable must be scalar and writeable,
        and the date string should be 11 characters at least.

        A  "radio  Julian date" (or "Jansky Julian date") starts as -2^15 on the
        date of the first radio observation by Karl Jansky. It is thus the Modi-
        fied  Julian date minus 60549. That choice was made to maximize the time
        interval over which radio astronomical data could be usefully stored  in
        an integer*2, back when 2 bytes of header space per spectrum were a sig-
        nificant consideration. This date has little meaning outside the  rather
        sparse community of souls gathered around the CLASS program, however.