Question

Hey I am looking to create a Julian date format like YYDDD from the current date where the DDD would be the number of days since the year began.

Is there any .NET functions to do this easily ?

Answer 1

Since, if you’re working with Julian dates, you probably will need to do this again and again, I suggest writing an extension function for System.DateTime, which would execute something like the following:

return (DateTime.Year % 100) * 1000 + DateTime.DayOfYear

ETA: If what you want to do is convert a DateTime to the Julian date format (create a formatted string in Julian date format), I still suggest an extension function, but it would look like this:

public static string ToJulianDate(this DateTime date) 
{
    return string.Format("{0:00000}", (date.Year % 100) * 1000 + date.DayOfYear);
}