A combination of cheap rail tickets and the long Whitsun holiday weekend has prompted a rush of day trippers to the German North Sea island of Sylt. The passenger trains were packed and the car trains were also fully booked, a photographer reported to dpa on Saturday afternoon. Many train passengers arrived in a party mood. This month the German government introduced a monthly flat rate ticket for just €9 ($9.65), with the first weekend of the offer falling on the Christian festival of Whitsun, or Pentecost. Monday is a holiday across Germany. The mayor of Sylt, Nikolas Häckel, told dpa on Sat…