Sorry I misunderstood the question initially.
Is this dataset likely to grow at all? If you have multiple "applicable" resuts for a single locations (like dubaiin ths example), I can quickly see this falling over. Making either the SQL need to be quite complex, or it may need to be done iteritively (eww) if you have quite a large list set of data for both times and locations.
Thom~
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does.
Larnu.uk