need to find time difference between two time strings

Hi I have two (as a sample) matlab serial date numbers which I want to find the gap between them. hours minutes and seconds. these are the time I have: d1 = 7.314983860995370e+005 d2 = 7.314983864467592e+005

any help is greatly appreciated

[David Young]

These are not strings. Are they MATLAB serial date numbers (i.e. do they both refer to 9 October 2002), or are they something else?

[H D]

thanks for your time. Yes you are right. serial date number is what they are, and the time is as you said. thanks for correction. I fixed the question also.

Answer 1

[Guillaume]

datetime(d2, 'ConvertFrom', 'datenum') - datetime(d1, 'ConvertFrom', 'datenum')

[H D]

thanks for your response. Unfortunately I am not able to use datetime as it is not defined in the version of matlam I am using. is there any other suggestion? or any help to use datetime in the older version of matlab (plug and play solution etc.)

[Guillaume]

You can also directly subtract datenums and convert them into date strings:

datestr(d2-d1, 'HH:MM:SS')

This works pre-2014b

[H D]

thanks in advance. It is working perfectly as you mentioned. I appreciate it

Answer 2

[David Young]

Something like this:

% Some data. Making the gap between d1 and d2 bigger than in your example
% to provide a better check on results
d1 = 7.314983860995370e+005;   % 09-Oct-2002 09:15:59
d2 = now;

% Difference in days
daydiff = d2 - d1;

% Subdivisions of days into hours, hours into mins, mins into secs
divisions = [1 24 60 60];

% Get number of days, hrs, mins and secs between times, rounded down
dhmsTotal = floor(daydiff * cumprod(divisions));
% Subtract days*24 from total hrs, etc., to get remainders
dhms = dhmsTotal - [0 dhmsTotal(1:end-1)] .* divisions;

dhms is now a vector with [days hours mins secs]. Note that the seconds are rounded down to whole seconds - if you want fractions of seconds, apply the floor function only to the first three elements of dhmsTotal.