Vädersolstavlan April 20: Easter (Christianity, 2025); first day of Ridván (Baháʼí Faith, 2025); 420 (cannabis culture) 1535 – Sun dogs were observed over Stockholm, Sweden, inspiring Vädersolstavlan (pictured), the oldest coloured depiction of the city. 1657 – Anglo-Spanish War: The English navy sank much of a Spanish treasure fleet at the Battle of Santa Cruz de Tenerife off the Canary Islands, but was unable to capture the treasure. 1968 – Pierre Trudeau was sworn in as prime minister of Canada, succeeding Lester B. Pearson. 2004 – An incomplete tunnel leading to the Nicoll Highway MRT station in Singapore collapsed, resulting in four deaths and the station's relocation. 2010 – An explosion on Deepwater Horizon, an offshore rig in the Gulf of Mexico, resulted in the largest marine oil spill in history. William Bedloe (b. 1650)David Brainerd (b. 1718)Frances Ames (b. 1920)Kojo Laing (d. 2017) More anniversaries: April 19 April 20 April 21 Archive By email List of days of the year About