MATLAB: How to turn a column of seconds into the datetime-type

datetimeMATLABtable

I have a table that looks like this:
TIME_s    SD1_SPEED_MEASURED_1_rpm    SD2_SPEED_MEASURED_1_rpm    SD3_SPEED_MEASURED_1_rpm    SD4_SPEED_MEASURED_1_rpm    SD1_MOTOR_SPEED_rpm    SD2_MOTOR_SPEED_rpm    SD3_MOTOR_SPEED_rpm    SD4_MOTOR_SPEED_rpm    SD1_MOTOR_TORQUE_pct    SD2_MOTOR_TORQUE_pct    SD3_MOTOR_TORQUE_pct    SD4_MOTOR_TORQUE_pct    SD1_TORQUE_REF_B_pct    SD2_TORQUE_REF_B_pct    SD3_TORQUE_REF_B_pct    SD4_TORQUE_REF_B_pct
    ______    ________________________    ________________________    ________________________    ________________________    ___________________    ___________________    ___________________    ___________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________    ____________________
     242.2      -66.174                    -69.167                      -77.607                     -74.388                      -66.369                 -69.19                -77.367                -73.986                -2.6341                -0.046144                0.34017                 -0.7492                  -1.97                 -2.3501                 -2.3501                 -2.3501           
    242.18      -66.174                    -69.167                      -77.607                     -74.388                      -66.369                 -69.19                -77.367                -73.986                -2.6341                -0.046144                0.34017                 -0.7492                  -1.97                 -2.3501                 -2.3501                 -2.3501           
    242.16      -68.547                    -72.838                       -79.49                     -77.035                      -68.078                -72.151                -78.954                -75.901                -2.8352                 -0.24927                -1.2125                 -4.7041                  -1.97                   -1.97                 -2.3501                 -2.3501           
    242.14      -68.547                    -72.838                       -79.49                     -77.035                      -68.078                -72.151                -78.954                -75.901                -2.8352                 -0.24927                -1.2125                 -4.7041                  -1.97                   -1.97                 -2.3501                 -2.3501           
    242.12      -71.372                    -75.556                      -80.754                     -79.204                       -70.49                -74.884                -80.715                -78.217                -3.1016                  -3.7407                -1.6364                 -2.9571                  -1.97                   -1.97                   -1.97                   -1.97         
    ...
    0            0                          0                            0                            0                            0                     0                      0
Where the leftmost column records the time that has passed since the beginning of the recording in seconds. In a separate variable, I have stored the starting time of the recording in the datetime-type. In this example, the time is this:
zinterval = 
datetime
18-Feb-2018 15:11:11
Now, is there any way to turn the value 0 in the column of seconds into the starting time, and then have all the following seconds be times in the datetime-type following the starting time?

Best Answer

The simple MATLAB solution using datetime and duration classes (no outdated datevec):
T.TIME_S = zinterval + seconds(T.TIME_s)
Note that using the variable name "TIME_s" is then a bit misleading (better would be "TIME" or something similar) and I would recommend avoiding overwriting your raw data. Here is a full working example:
>> T = array2table([242.2;242.18;242.16;242.14;242.12;0],'VariableNames',{'TIME_s'})
T = 
    TIME_s
    ______
     242.2
    242.18
    242.16
    242.14
    242.12
         0
>> zinterval = datetime('18-Feb-2018 15:11:11')
zinterval = 
   18-Feb-2018 15:11:11
>> T.TIME = zinterval + seconds(T.TIME_s)
T = 
    TIME_s            TIME        
    ______    ____________________
     242.2    18-Feb-2018 15:15:13
    242.18    18-Feb-2018 15:15:13
    242.16    18-Feb-2018 15:15:13
    242.14    18-Feb-2018 15:15:13
    242.12    18-Feb-2018 15:15:13
         0    18-Feb-2018 15:11:11
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