code: def to_jd2(year, month, day):
      '''Gregorian to Julian Day Count for years between 1801-2099'''
      # http://quasar.as.utexas.edu/BillInfo/JulianDatesG.html
  
      legal_date(year, month, day)
  
      if month <= 2:
          year = year - 1
          month = month + 12
  
      a = floor(year / 100)
      b = floor(a / 4)
      c = 2 - a + b
      e = floor(365.25 * (year + 4716))
      f = floor(30.6001 * (month + 1))
      return c + day + e + f - 1524.f to_jd2(year, month, day):
      '''Gregorian to Julian Day Count for years between 1801-2099'''
      # http://quasar.as.utexas.edu/BillInfo/JulianDatesG.html
  
      legal_date(year, month, day)
  
      if month <= 2:
          year = year - 1
          month = month + 12
  
      a = floor(year / 100)
      b = floor(a / 4)
      c = 2 - a + b
      e = floor(365.25 * (year + 4716))
      f = floor(30.6001 * (month + 1))
      return c + day + e + f - 1524.5
docs: Gregorian to Julian Day Count for years between 1801-2099