NAME: day_to_year_doy PURPOSE: determines year and day of year given day since 0000 AD USAGE: day_to_year_doy,daynum,year,doy INPUT: daynum: (long int) day since 0 AD OUTPUT: year: year (0 <= year <= 14699 AD) doy: day of year (1 <= doy <= 366) NOTES: This procedure is reasonably fast, it works on arrays and works from 0 AD to 14699 AD CREATED BY: Davin Larson Oct 1996 FILE: day_to_year_doy.pro VERSION: 1.2 LAST MODIFICATION: 97/01/27