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[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.