val=['17-10-58_086'
'17-11-09_923'];
val = string(val);
Convert the string array val into a format the duration function knows how to import.
val = replace(val, '-', ':');
val = replace(val, '_', '.');
d = duration(val)
The fractional seconds are present, they're just not displayed with the default display Format. We can change the Format to show them.
d.Format = 'hh:mm:ss.SSS'
Now compute the difference in seconds.
seconds(diff(d))
