Correcting timestamp from netCDF

Hello to matlab the community,

If possible I would be grateful for some help in regards to conversion of timestamps in matlab from netcdf.

I am familiar with netcdf and their structure as well as their conversion, but I think I am missing something.

I have a netcdf with time in the format of

time =[23627;
23627.0069444444;
23627.0138888889;
23627.0208333333];

And I am trying to correct the timestamp both to a human readable form but also to use in plots.

Of course I checked the time offset in the netcdf and it is in

"days since 1950-01-01T00:00:00Z";

Therefore, I have included this offset in my estimates but I cannot see to be getting the correct form. I am using this

time_offset=datenum(1950,01,01);
new_time=(time/24)+time_offset; 
timestamp=datestr(new_time);
timestamp=datestr(new_time,'yyyymmddHHMM');
nt=str2num(timestamp);
timestamp=uint64(nt);
timestamp=double(nt);

However the outcome does not give me what I would expect.

The measurements should be in 10 minute increments like so:

01-01-2015 00:00:00
01-01-2015 00:10:00

The variable is new_time is estimated as

7.132084583333334e+05

that corresponds to the variable timestamp:

195209111100

It seems that it does not recognize the offset. Have I done anything wrong?

Thank you all in advance,

Answer 1

[Peter Perkins]

>> time = [23627 23627.0069444444 23627.0138888889 23627.0208333333];
>> dt = datetime(1950,1,1,'Format','dd-MMM-yyyy HH:mm:ss') + days(time)
dt = 
  1×4 datetime array
   09-Sep-2014 00:00:00   09-Sep-2014 00:09:59   09-Sep-2014 00:20:00   09-Sep-2014 00:29:59

I guess netCDF timestamps are UTC? The above will work for that, in general, you'd want to use caldays to account for DST shifts twice a year.

[George Lavidas]

Peter thank you very much for this answer, this is quite different and much faster from I had been using thanks.