City history
From Old Norse origins to Danish royal renaming and standard time adoption in 1895, Oslo's history reflects shifting national identity and scientific timekeeping.
Chapter one
Earliest documented name
"Meadow beneath the ridge or meadow sacred to the gods"
Recorded in 11th-century sagas, the earliest documented name Ánslo (later Áslo or Óslo) combines Old Norse 'ás' (referring either to the Ekeberg ridge or the Æsir gods) and 'ló' (meadow). No pre-existing Indigenous Sámi name for the settlement is documented in early historical records.
Meadow beneath the ridge or sacred meadow
Founded in the 11th century, medieval Oslo served as Norway's capital from around 1300 under King Haakon V. The Old Norse name persisted through centuries until a catastrophic citywide fire in August 1624 completely destroyed the wooden settlement.
Named in honor of King Christian IV
After the 1624 fire, King Christian IV of Denmark-Norway rebuilt the city in stone and brick closer to Akershus Fortress for fire protection, officially renaming it Christiania in his honor. The ruined original site remained a small suburb called Oslo.
Norwegianized spelling of Christiania
Following a national linguistic reform that replaced Danish 'Ch' spellings with Norwegian 'K', the state adopted 'Kristiania' in 1877, followed by municipal authorities in 1897. The spelling reflected growing Norwegian national identity leading to full independence in 1905.
Restoration of the historic medieval Old Norse name
On January 1, 1925, the Norwegian parliament formally restored the medieval name Oslo for the entire capital. The decision reclaimed pre-union Norwegian heritage, while the old suburb previously called Oslo was renamed Gamlebyen, meaning the Old Town.
Chapter two
On January 1, 1895, Norway adopted Central European Time (UTC+01:00) as its unified national standard. Before this legislation, Oslo relied on local solar time, and Norwegian railways operated on fragmented local time standards across different regional lines.
Norway introduced Daylight Saving Time for the first time in May 1916 alongside several European nations during World War I to conserve coal and electric energy. The seasonal clock adjustment was discontinued following the end of the war.
During World War II, Norway reintroduced daylight saving in April 1940. Clocks were maintained one hour ahead throughout winter from late 1940 to late 1942, before resuming standard summer shifts until wartime regulations ended in 1945.
After a trial period between 1959 and 1965, Norway formally reinstated annual Daylight Saving Time in 1980. The nation synchronized its summer clock changes with European neighbors, shifting to Central European Summer Time (UTC+02:00) every spring.
Chapter three
Designed by Christian Heinrich Grosch and astronomer Christopher Hansteen, the University Observatory at Solli opened in 1833. It established Norway's zero meridian and calculated local mean solar time, serving as the nation's primary astronomical and timekeeping authority.
The opening of Norway's first electrical telegraph line between Oslo and Drammen required synchronized clock time. Railway lines out of Oslo's eastern and western stations initially used local time standards before full national standardization took place in 1895.
Oslo City Hall was officially inaugurated in 1950, featuring a massive tower clock and a 49-bell carillon in the East Tower, along with a complex astronomical clock on the West Tower façade that plays hourly tunes across the harbor.
On October 20, 2010, the Oslo Astrological Clock was unveiled on Karl Johans gate. Designed by Norwegian artists Elena Engelsen and Per Ung, the gilded 3.46-meter clock showcases bronze astrological symbols and custom artwork in the city center.