Tenho uma tabela de visitas (id int, data e hora de início e data final) e você deseja acompanhar as contagens de pico de visitas.

Dados de exemplo:

+------+---------------------+---------------------+
| id   | date-time-1         | date-time-2         |
+------+---------------------+---------------------+
| 1059 | 2016-07-04 19:13:00 | 2016-07-04 19:20:05 |
| 1060 | 2016-07-04 19:13:30 | 2016-07-04 19:14:25 |
| 1061 | 2016-07-04 19:14:39 | 2016-07-04 19:20:05 |
| 1062 | 2016-07-05 02:34:40 | 2016-07-05 02:45:23 |
| 1063 | 2016-07-05 02:34:49 | 2016-07-05 02:45:34 |
+------+---------------------+---------------------+

O resultado esperado deve ser:

+-------------------------------------------+-------+ 
| date-time-1         | date-time-2         | count | 
+-------------------------------------------+-------+ 
| 2016-07-04 19:13:00 | 2016-07-04 19:13:29 | 1     | 
| 2016-07-04 19:13:30 | 2016-07-04 19:14:25 | 2     | 
| 2016-07-04 19:14:26 | 2016-07-04 19:14:38 | 1     | 
| 2016-07-04 19:14:39 | 2016-07-04 19:20:05 | 2     | 
| 2016-07-04 19:20:06 | 2016-07-05 02:34:39 | 0     | 
| 2016-07-05 02:34:40 | 2016-07-05 02:34:48 | 1     | 
| 2016-07-05 02:34:49 | 2016-07-05 02:45:23 | 2     | 
| 2016-07-05 02:45:24 | 2016-07-05 02:45:34 | 1     | 
+------+------------------------------------+-------+