Conversion of seconds to date

Hello,

I have a datasets with time expressed in seconds since 1950-01-01 00:00:00. The two times I would like to convert are : [1907798400] and [1908230400]. I would like to convert them in a date format (Yr-Mnth-Day Hr:min:sec) I previously look on the forum to help me and I did the following steps :

base = datenum(1950,1,1);
datestr([1907798400]/86400) + base)
>> '16-Jun-2010'

base = datenum(1950,1,1);
datestr([1908230400]/86400) + base)
>> '21-Jun-2010'

However, I expect to obtain dates in the months of July 2010. Also, when I open the datasets using Panoply, I obtain the following dates : 2010-07-01 00:00:00 - 2010-07-06 00:00:00. (Yr-Mnth-Day Time)

This is more likely to be what I expect. However, I don't understand why using Matlab I obtain different dates? The year is correct (2010), but not the month. Is there something I am doing wrong?

Could you help me solve this issue?

Thank you a lot for your help.

Regards

Answer 1

[James Tursa]

MATLAB is giving you the result of June 16, 2010 because that is the correct answer for the input of 1907798400. This matches intuition as well, e.g. a crude calculation:

>> (1907798400/86400)/365.25
ans =
   60.4545

So you would expect the answer to be 60 years and slightly less than 1/2 year later than the base, which we could easily expect to be in June 2010.

The datetime( ) function also agrees with this:

>> datetime(1950,1,1) + seconds(1907798400)
ans = 
  datetime
   16-Jun-2010 00:00:00

or

>> datetime(1950,1,1,0,0,1907798400)
ans = 
  datetime
   16-Jun-2010 00:00:00

Are you sure you are using the same inputs when you compare the MATLAB results to the Panoply results?

[Peter Perkins]

Also:

>> d = datetime([1907798400 1908230400],'ConvertFrom','epochtime','Epoch','01-Jan-1950 00:00:00')
d = 
  1×2 datetime array
   16-Jun-2010 00:00:00   21-Jun-2010 00:00:00

Answer 2

[Valérie Le Guennec]

Hi all, Thank you very much for all your replies. It really helped me. Sincerely

[Ozan Akyildiz]

Why is this the accepted answer? This is not helping the reader. I suggest Posting the answer you found as an "Answer" then selecting it.