How to convert these char values to datetime format?

Hello everyone,

I tried to do this operation to get the duration between both datetimes as follows:

% starting date-time 
date_obs = char('2017/09/06'); 
time_obs = char('11:55:01.109'); 
% ending date-time 
date_end = char('2017/09/06'); 
time_end = char('12:10:01'); 
% combining dates & times 
datetime_start = strcat(date_obs,{' '},time_obs); 
datetime_end = strcat(date_end,{' '},time_end); 
%% DATETIMES 
datetime1 = datetime(datetime_start,'InputFormat','yyyy/MM/dd HH:mm:ss'); 
datetime2 = datetime(datetime_end,'InputFormat','yyyy/MM/dd HH:mm:ss'); 

But I get this error:

Unable to convert '2017/09/06 11:55:01.109' to datetime using the format 'yyyy/MM/dd HH:mm:ss'.

Can you please tell me how to convert them to datetime and get the difference (duration) between both?

I appreciate your help!

Thank you,

Answer 1

[Stephen23]

The error is caused by the milliseconds in start string: either you need to remove them from the input string, or specify them in the Input format:

>> datetime1 = datetime(datetime_start,'InputFormat','yyyy/MM/dd HH:mm:ss.SSS')
datetime1 = 
   06-Sep-2017 11:55:01

It is not permitted to have unused characters left over, all characters must correspond to something in the format string. After that it is trivial to calculate the difference (and generate a duration object):

>> dtdiff = datetime2-datetime1
dtdiff = 
   00:14:59

[Mohamed Nedal]

Thank you very much

[Patryk Sapiega]

What will it look like in version 2014a where this feature is missing?

[Stephen23]

"What will it look like in version 2014a where this feature is missing?"

DATETIME was introduced in R2014b, so you would need to use deprecated date functions, e.g.:

N1 = datenum('2017/09/06 11:55:01.109','yyyy/m/d HH:MM:SS.FFF');
N2 = datenum('2017/09/06 12:10:01','yyyy/m/d HH:MM:SS');
DD = datestr(N2-N1,'HH:MM:SS.FFF')

DD = '00:14:59.891'