time   calls  line
                  1 function [year, month, day, hour, minute, second] = jd2date(jd)
                  2 %JD2DATE Gregorian calendar date from modified Julian day number.
                  3 %
                  4 %   [YEAR, MONTH, DAY, HOUR, MINUTE, SECOND] = JD2DATE(JD) returns the
                  5 %   Gregorian calendar date (year, month, day, hour, minute, and second)
                  6 %   corresponding to the Julian day number JD.
                  7 %
                  8 %   Start of the JD (Julian day) count is from 0 at 12 noon 1 JAN -4712
                  9 %   (4713 BC), Julian proleptic calendar.  Note that this day count conforms
                 10 %   with the astronomical convention starting the day at noon, in contrast
                 11 %   with the civil practice where the day starts with midnight.
                 12 %
                 13 %   Astronomers have used the Julian period to assign a unique number to
                 14 %   every day since 1 January 4713 BC.  This is the so-called Julian Day
                 15 %   (JD). JD 0 designates the 24 hours from noon UTC on 1 January 4713 BC
                 16 %   (Julian calendar) to noon UTC on 2 January 4713 BC.
                 17 
                 18 %   Sources:  - http://tycho.usno.navy.mil/mjd.html
                 19 %             - The Calendar FAQ (http://www.faqs.org)
                 20 
                 21 %   Author:      Peter J. Acklam
                 22 %   Time-stamp:  2002-05-24 15:24:45 +0200
                 23 %   E-mail:      pjacklam@online.no
                 24 %   URL:         http://home.online.no/~pjacklam
                 25 
           123   26    nargsin = nargin; 
           123   27    error(nargchk(1, 1, nargsin)); 
                 28 
                 29    % Adding 0.5 to JD and taking FLOOR ensures that the date is correct.
                 30    % Here are some sample values:
                 31    %
                 32    %  MJD     Date       Time
                 33    %  -1.00 = 1858-11-16 00:00 (not 1858-11-15 24:00!)
                 34    %  -0.75 = 1858-11-16 06:00
                 35    %  -0.50 = 1858-11-16 12:00
                 36    %  -0.25 = 1858-11-16 18:00
                 37    %   0.00 = 1858-11-17 00:00 (not 1858-11-16 24:00!)
                 38    %  +0.25 = 1858-11-17 06:00
                 39    %  +0.50 = 1858-11-17 12:00
                 40    %  +0.75 = 1858-11-17 18:00
                 41    %  +1.00 = 1858-11-18 00:00 (not 1858-11-17 24:00!)
                 42 
           123   43    ijd = floor(jd + 0.5);               % integer part 
                 44 
           123   45    if nargout > 3 
           122   46       fjd = jd - ijd + 0.5;             % fraction part 
  0.01     122   47       [hour, minute, second] = days2hms(fjd); 
           122   48    end 
                 49 
                 50    % The following algorithm is from the Calendar FAQ.
                 51 
           123   52    a = ijd + 32044; 
           123   53    b = floor((4 * a + 3) / 146097); 
           123   54    c = a - floor((b * 146097) / 4); 
                 55 
           123   56    d = floor((4 * c + 3) / 1461); 
           123   57    e = c - floor((1461 * d) / 4); 
           123   58    m = floor((5 * e + 2) / 153); 
                 59 
           123   60    day   = e - floor((153 * m + 2) / 5) + 1; 
           123   61    month = m + 3 - 12 * floor(m / 10); 
           123   62    year  = b * 100 + d - 4800 + floor(m / 10);