This code will work:
dt = New Table( "Test", Add Rows( 3 ),
New Column( "ID", Character, "Nominal",
Set Values( {"71220G1", "80102G1", "80209G1"} )
),
New Column( "Date", Numeric, "Continuous", Format( "m/d/y", 12 ),
Input Format( "m/d/y" ),
Set Values( [3597868800, 3597955200, 3601843200] )
)
);
dt << sort(replace table(1), by(:Date));
id_values = dt:ID << get values;
dt:id << Set Property( "Value Ordering", id_values );
If you have multiple dates for a given ID you'll have to take a different approach.