However in the mainframe world, we call them 'Julian Dates', and so we've used this term on this page.Instructions: Use this tool to convert between date and Julian (yyddd) date formats.However technically, a Julian date can mean different things.Astronomers refer to a Julian date as the number of days since the beginning of the Julian Period (January 1, 4713 BC).
The ".3423000001348555" represented the time of day (" EST").Many applications store dates in 5-digit long Julian format, which consists of a 2 digit year and a 3 digit day-of-year number.We refer to a yyddd date format (yy = year, ddd=day) as a 'Julian Date' - this is the common term for such a date in mainframe and other circles.Julian date is considered to be the number of elapsed days since the beginning of a particular year.For example, the Julian date in 3-digit format for the calendar date of 2012-02-15 would be 46 or 046.Julian date is widely used in the fields of earth sciences, computer programming, astronomy, military and food industry.In computer programming, the meaning of Julian date changes sometimes.The Julian Day Number (JDN) is the integer assigned to a whole solar day in the Julian day count starting from noon Universal time, with Julian day number 0 assigned to the day starting at noon on Monday, January 1, 4713 BC, proleptic Julian calendar (November 24, 4714 BC, in the proleptic Gregorian calendar), The Julian date (JD) of any instant is the Julian day number plus the fraction of a day since the preceding noon in Universal Time.Julian dates are expressed as a Julian day number with a decimal fraction added.A Julian date(JD) is the elapsed time in days and fractions of a day since January 1, 4713 BC Greenwich noon.The purpose of the Julian date is to make it easy for computing difference between one calendar date and another calendar date.The Julian (*JUL) date format is CYYDDD, where: C is added to 19 to create the century, i.e. YY is the year within the century, DDD is the day in the year. For dates in the Julian calendar, see Julian calendar. For the comic book character Julian Gregory Day, see Calendar Man.These conversion charts will assist in determining the value to enter.