Explanation
If you better group times into buckets (i.e.
group by 6 hours, group by 3 hours, etc.)
you might do so with a rounding function called FLOOR.
In the example shown, we have a number of transactions, each with a timestamp.
A time of 8:45 AM needs to go into the 6:00 AM-9:00 AM bucket, and so on.
FLOOR works like the MROUND function, but FLOORalways rounds down.
