Here's how to do it in JMP:
This code creates the table you listed:
dt = New Table( "My Cases", Add Rows( 2 ),
New Column( "Case ID", Character, Nominal,
Set Values( {"BNZ123-2424", "BNZ123-2425"} )
),
New Column( "Date", Character, Nominal,
Set Values( {"30/9/2011 1:34:00 PM", "31/9/2011 1:34:00 PM"} )
)
);
The next block of code creates a new column called Monthly Date, which uses a formula based on the Date column. You can use Monthly Date on the X axis in graph builder.
dt << New Column( "Monthly Date", Numeric, Nominal, Format( "m/y", 12 ),
Input Format( "m/y" ),
Formula(
date_list = Words( :Date, "/ " );
Informat( date_list[2] || "/" || date_list[3], "m/y" );
),
);
This block of code creates a new column called Monthly Date, which uses a formula based on the Date column. You can use Monthly Date on the X axis in graph builder.