If you where to calculate pivot points for trading would you use 5pm to 5pm EST ( <A HREF="http://www.allpivotpoints.com/pivot_points/pivotcore-exchange-forex-symbol-EURUSD.html" target="_blank">http://www.allpivotpoints.com/pivot_points/pivotcore-exchange-forex-symbol-EURUSD.html</A> ) or 7PM to 7PM EST? What do the pros use?