[Question] How would i find duplicate timings in this dataset

I have a data set that is like this which is stored as a string in an array of objects

Timestamp --------- 2016/07/27 21:15:25.394 2016/07/27 21:23:38.598 2016/07/27 21:40:56.448 2016/07/27 21:40:56.449 2016/07/27 21:40:58.084 2016/07/27 21:53:30.256 2016/07/27 21:56:39.087 2016/07/27 21:56:39.088 2016/07/27 21:56:39.089 2016/07/27 22:19:20.548 2016/07/27 22:19:20.549 2016/07/27 22:19:20.550 2016/07/27 22:19:20.550 2016/07/27 22:19:20.551 2016/07/27 22:19:20.552 2016/07/27 22:34:03.332 2016/07/27 22:57:30.530 2016/07/27 23:21:37.222 2016/07/27 23:21:37.223 2016/07/27 23:21:37.224 2016/07/27 23:21:37.224 

I need to find all timings which have entries within less than a few milliseconds of each other.

I’m not sure how I would do this, anyone able to help?

edit: Not sure explained it correctly.

2016/07/27 22:19:20.548 2016/07/27 22:19:20.549 2016/07/27 22:19:20.550 2016/07/27 22:19:20.550 2016/07/27 22:19:20.551 2016/07/27 22:19:20.552 2016/07/27 23:21:37.222 2016/07/27 23:21:37.223 2016/07/27 23:21:37.224 2016/07/27 23:21:37.224 

These entries I am intrested in so it would return 2 because there are 2 occurrences of these entries