Look at the help file for timetable. You should be able to access the 1st column with the dot notation.
Following example is straight from the help file.
MeasurementTime = datetime({'2015-12-18 08:03:05';'2015-12-18 10:03:17';'2015-12-18 12:03:13'});
Temp = [37.3;39.1;42.3];
Pressure = [30.1;30.03;29.9];
WindSpeed = [13.4;6.5;7.3];
WindDirection = categorical({'NW';'N';'NW'});
TT = timetable(MeasurementTime,Temp,Pressure,WindSpeed,WindDirection)
Now reference as
>> TT.MeasurementTime
ans =
3×1 datetime array
18-Dec-2015 08:03:05
18-Dec-2015 10:03:17
18-Dec-2015 12:03:13
You could of course convert to a (normal) table, or even an array.
