Convert netcdf time ('minutes since 2013-2-1 00:00:00') to actual date

Hi all;

I have netcdf file. When I use ncdisp on the netcdf file, time is described as the following:

XTIME

Size: 22177x1

Dimensions: XTIME

Datatype: double

Attributes:

standard_name = 'time'

units = 'minutes since 2013-2-1 00:00:00'

calendar = 'standard'

axis = 'T'

netcdf_time = ncread('data.nc','XTIME'), provide

60

120

180

240

300

360

420

...

I used the following code to convert XTIME to actual date,

t1 = double(netcdf_time) + datenum('2013-2-1 00:00:00');

t2 = datevec(t1);

However, the result is not correct, as below

2013 4 2 0 0 0

2013 6 1 0 0 0

2013 7 31 0 0 0

...

Actual date should be hourly time fomat.

If any of friends here have any experience with this problem, please share it. I really thank you for that.

Answer 1

[Steven Lord]

I recommend using datetime rather than datenum.

netcdf_time = 60:60:300 % Sample data

netcdf_time = 1×5

60 120 180 240 300

epoch = datetime(2013, 1, 2) % Assuming January 2nd, swap the 1 and 2 for February 1st

epoch = datetime
   02-Jan-2013

T = epoch + minutes(netcdf_time)

T = 1×5 datetime array
   02-Jan-2013 01:00:00   02-Jan-2013 02:00:00   02-Jan-2013 03:00:00   02-Jan-2013 04:00:00   02-Jan-2013 05:00:00

[Marzuki Marzuki]

Thank you @Steven Lord It works

Answer 2

[Bjorn Gustavsson]

Remember that datenum is in (fractional) days, while your netcdf-time is in minutes. It seems likely that you want to do:

t1 = double(netcdf_time)/60/24 + datenum('2013-2-1 00:00:00'); 

HTH

[Marzuki Marzuki]

Thank you @Bjorn Gustavsson it works too.