Calls dashlet - sort by date AND time

[ChocolateLover]

I'd like to be able to sort calls in the Calls Dashlet by start time AND start date.
e.g.
This is the correct sort
02-23-2007 9:00
02-24-2007 9:30
02-24-2007 13:30


This is the incorrect sort
02-23-2007 9:00
02-24-2007 13:30
02-24-2007 9:30

I've added start time to the list view but this gives me a start time OR start date sort.

I can either

1) concatenate the date and time within the MySQL string - something like CONCAT( date_start, CONCAT(' ', time_start ) ) AS date_start
I can't see where to add this to the query

2) similar to 2, but create a new field - CONCAT( date_start, CONCAT(' ', time_start ) ) AS date_time_start
Again, I can't see where to add this to the query.

If I did use CONCAT - would this give me a useable (sortable) date/time result?

Is there a way to set a field that the query sorts on by default? And set it to ascending or descending?

I'd be grateful for any help.

Thanks.