H-dagurinn in Iceland: Traffic changes from driving on the left to driving on the right overnight.

H-dagurinn or Hægri dagurinn on 26 May 1968 was the day that Iceland changed from left hand traffic to right hand traffic. The change itself occurred formally at 6:00 am.

May 26 is the 146th day of the year in the Gregorian calendar; 219 days remain until the end of the year.