julian-date

Julian Day Numbers are a means of representing timestamps as a continuous count of days (and fractional days) since noon UTC, January 1, 4713 B.C. The Java 7 SE API does not contain support for this format. Developers who have used the SQLite database may have used the native Julian Day support provided by the strftime() functions. The advantages of representing timestamps as Julian Day Numbers include: A date and time can be represented to millisecond precision in a primitive data type (double) Days in a year are somewhat more concrete than seconds in a day Circumvents the problem of "leap

Try running this in iOS6 (haven't tested pre iOS6): NSDateFormatter *julianDayDateFormatter = nil; julianDayDateFormatter = [[NSDateFormatter alloc] init]; [julianDayDateFormatter setDateFormat:@"g"]; for (NSString *timeZone in [NSTimeZone knownTimeZoneNames]) { julianDayDateFormatter.timeZone = [NSTimeZone timeZoneWithName: timeZone]; NSDate *date = [julianDayDateFormatter dateFromString:[NSString stringWithFormat:@"%d", 2475213]]; if (date == nil) NSLog(@"timeZone = %@", timeZone); } and you get the following output: America/Bahia America/Campo_Grande America/Cuiaba America/Sao_Paulo Can

I am writing code to convert from a Gregorian date to a JDE ( J.D.Edwards ) Julian date. Note: a JDE Julian date is different from the normal usage of the term Julian date . As far as I can work out from Googling, the definition of a JDE Julian date is: 1000*(year-1900) + dayofyear where year is the 4-digit year (e.g. 2009), and dayofyear is 1 for 1st January, and counts up all year to either 365 or 366 for 31st December (depending whether this is a leap year). My question is this: are years before 1900 supported? If so, does the above formula still hold, or should it be this: 1000*(year-1900)

I have seen the "solution" at http://www.rgagnon.com/javadetails/java-0506.html , but it doesn't work correctly. E.g. yesterday (June 8) should have been 159, but it said it was 245. So, does someone have a solution in Java for getting the current date's three digit Julian day (not Julian date - I need the day this year)? Thanks! Mark If all you want is the day-of-year, why don'you just use GregorianCalendars DAY_OF_YEAR field? import java.util.GregorianCalendar; public class CalTest { public static void main(String[] argv) { GregorianCalendar gc = new GregorianCalendar(); gc.set

I have a column of dates in the format: 16Jun10 and I would like to extract the Julian day. I have various years. I have tried the functions julian and mdy.date and it doesn't seem to work. Try the following to convert from class character (i.e. text) to class POSIXlt , and then extract Julian day ( yday ): tmp <- as.POSIXlt("16Jun10", format = "%d%b%y") tmp$yday # [1] 166 For more details on function settings: ?POSIXlt ?DateTimeClasses Another option is to use a Date class, and then use format to extract a julian day (notice that this class define julian days between 1:366, while POSIXlt is 0

I have a year value and a day of year and would like to convert to a date (day/month/year). Thanks in advance. :) datetime.datetime(year, 1, 1) + datetime.timedelta(days - 1) >>> import datetime >>> datetime.datetime.strptime('2010 120', '%Y %j') datetime.datetime(2010, 4, 30, 0, 0) >>> _.strftime('%d/%m/%Y') '30/04/2010' The toordinal() and fromordinal() functions of the date class could be used: from datetime import date date.fromordinal(date(year, 1, 1).toordinal() + days - 1) >>>import datetime >>>year = int(input()) >>>month = int(input()) >>>day = int(input()) data = datetime.datetime

I need to convert from a standard Gregorian date to a Julian day number. I've seen nothing documented in C# to do this directly, but I have found many posts (while Googling) suggesting the use of ToOADate . The documentation on ToOADate does not suggest this as a valid conversion method for Julian dates. Can anyone clarify if this function will perform conversion accurately, or perhaps a more appropriate method to convert DateTime to a Julian formatted string. This provides me with the expected number when validated against Wikipedia's Julian Day page public static long ConvertToJulian