+-------------------------------------------------------------------+
|Route |Sequence|        Planned Time       |     Business Date     |
+-------------------------------------------------------------------+
| 10-1 |   1    |  2015-08-21 20:15:00.000  |      2015-08-21       |
| 10-1 |   2    |  2015-08-22 00:30:00.000  |      2015-08-21       |
| 10-1 |   3    |  2015-08-22 08:45:00.000  |      2015-08-21       |
| 22-1 |   1    |  2015-08-20 17:30:00.000  |      2015-08-20       |
| 22-1 |   2    |  2015-08-21 01:10:00.000  |      2015-08-20       |
| 22-1 |   3    |  2015-08-21 06:30:00.000  |      2015-08-20       |
+------+--------+---------------------------+-----------------------+

SELECT
  [Route],
  [Sequence] = ROW_NUMBER() OVER
    (PARTITION BY [Route] ORDER BY [Planned Time]),
  [Planned Time],
  [Business Date] = MIN(CONVERT(DATE, [Planned Time])) OVER
    (PARTITION BY [Route])
FROM dbo.table_name
ORDER BY [Route], [Sequence];