A SAS date value is
a number that represents the number of days from January 1, 1960 to
a specific date. The JULDATE function converts a SAS date value to
a Julian date. If date
within the 100-year span defined by the system option YEARCUTOFF=,
the result has three, four, or five digits. In a five digit result,
the first two digits represent the year, and the next three digits
represent the day of the year (1 to 365, or 1 to 366 for leap years).
Because leading zeros are dropped from the result, the year portion
of a Julian date might be omitted (for years ending in 00), or it
might have only one digit (for years ending 01–09). Otherwise,
the result has seven digits: the first four digits represent the year,
and the next three digits represent the day of the year. For example,
if YEARCUTOFF=1920, JULDATE would return 97001 for January 1, 1997,
and return 1878365 for December 31, 1878.