Calculate difference between two times?...something it's wrong here¡

I would be very grateful if someone could help me with the following problem, I try to subtract dates, but clearly the result is not what I expect....look¡

>>date =

        2012           9          25           0           0           0
        2012           9          23          21           0           0

>>d=datenum(date)

d =

   1.0e+05 *

    7.3514
    7.3514

>>difference=d(1)-d(2);

ans =

    1.1250

>>datestr(difference,'yyyy mm dd HH MM SS')

ans =

0000 01 01 03 00 00 % should be 0000 00 01 03 00 00

Thanks

Answer 1

[Star Strider]

In the datevec documentation, this appears:

Limitations

• When computing date vectors, MATLAB sets month values less than 1 to 1. Day values, D, less than 1 are set to the last day of the previous month minus D. However, if 0 ≤ DateNumber < 1, then datevec(DateNumber) returns a date vector of the form [0 0 0 H MN S], where H, MN, and S are hours, minutes, and seconds, respectively.

This does not appear in the datestr documentation, but I would be surprised if it does not apply there as well, since both datestr and datevec give the same results to your calculations.

Answer 2

[José-Luis]

What makes you think it should be 0000 00 01 03 00 00?

From the documentation:

A serial date number represents a calendar date as the number of days that has passed since a fixed base date. In MATLAB, serial date number 1 is January 1, 0000.

If you subtract two datenumbers, the result will not be the time elapsed between the two dates.

 datevec(723300 - 723297)

If you want the elapsed time:

 etime(datevec(723300),datevec(723297))  %in seconds

[Oleg Komarov]

For instance, the abse date is January 0, 0000:

datestr(0,'yyyy mm dd') 
ans = 
    0000 01 00

[Rapala]

Thank You So Much ¡

[José-Luis]

Please accept the answer that best solves your problem.