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
Best Answer