Elapsed time.

DataTable or InfoTable?

Infotable:

var timeBetween = dateDifference(yourInfotable.rows[0][timestampField],yourInfotable.rows[yourInfotable.rows.length-1][timestampField]);

DataTable:

var yourInfotable = yourDataTable.GetGetDataTableEntries({ maxItems: 1000000 });
// -- Here the previous code, you may need to sort the yourInfotable by timestampField...