Sell Tech Based on the Calendar? It Depends on Your Horizon

Last Tuesday night, Jim Cramer told his Mad Money viewers that they should sell tech based on the calendar.  His recomendation was based on the premise that historically speaking, the sector is entering its weakest part of the year.  As the chart below shows, he has a point.  Based on the last five years of trading (green line), from now (red dot) until August the sector generally doesn't do well.  However, if we take a longer time horizon going back to 1990 (blue line), the first half of the year hasn't been so bad.