MySQL

Got a mySQL question,

  I'm trying to figure out the best way of doing this I have a table for time slots, and what I want is to have a groups of these slots with ids unique to the group.

Would it be better to use a junction table or would the way it is work just fine?

+------------+------------+---------+------------+
|  Group Id  |   Slot id  |   Time  |    Date    |
+------------+------------+---------+------------+
|     1      |      1     | 2 bongs | Nov 5 1605 |
+------------+------------+---------+------------+
|     1      |      2     | 3 bongs | Nov 5 1605 |
+------------+------------+---------+------------+
|     2      |      1     | 1 bongs | Nov 12 1605|
+------------+------------+---------+------------+
|     2      |      2     | 7 bongs | Nov 12 1605|
+------------+------------+---------+------------+

nevermind I guess it doesn't hurt to have slot id be unique and just increment through the groups and aggregate the slot id's by the group id.