how to get the value in julian date and time

suppose we have 2014-04-29 4:35:22 date and time then how to convert the date and time together in julian, keeping 2000 as a starting reference.

[Michael Soskind]

Is there a reason that the function juliandate does not work for you? Are you using Matlab 2014b or newer?

[MONICA RAWAT]

i am using matlab 2019a

Answer 1

[Kelly Kearney]

Can you explain what you're defining as "Julian date"? While the 4714 BCE reference date is the proper one for a real Julian date, I know the term is often used in my field to mean either day-of-year or days-since-reference-date. My guess is you want the last option, in which case

tstr = '2014-04-29 4:35:22';
jd = days(datetime(tstr) - datetime(2000,1,1))

[MONICA RAWAT]

thank you so much kelly

Answer 2

[Michael Soskind]

Hi Monica,

The following code should work for your example:

% Julian Date Example 
% modified from https://www.mathworks.com/help/matlab/ref/datetime.juliandate.html

t1 = datetime('2014-04-29 4:35:22');        % Time input in traditional datetime format
t1.TimeZone = 'America/New_York'            % Setting the timezone

% Printing the Julian date as the number of days and fractional days since 
% noon on November 24, 4714 BCE
format longG                                % Defining the format to print Julian Date
jd1 = juliandate(t1)   

Hope that helps,

Michael

[MONICA RAWAT]

yeah i tried this,but the reference point is from November 24, 4714 BCE, but i want from 2000

[Michael Soskind]

Sorry I misinterpretted the question; Kelly just answered that for you, below.