Summadayze is an annual Australian music festival held in the month of January.
 The first event occurred on 1 January 1998 at the Sidney Myer Music Bowl in Melbourne.
 It has since expanded into a four city festival including one in New Zealand.
 Summadayze is organised by Future Entertainment.
The 1981 Southeast Asian Games, officially known as the 11th Southeast Asian Games was a multi-sport event held in Manila, Philippines from 6 to 15 December 1981.
 This was the first time that the Philippines hosted the Games since its first participation in 1977.
 Philippines is the sixth nation to host the Southeast Asian Games after Thailand, Burma, Malaysia, Singapore and Indonesia.
 The event was officially opened by President Ferdinand Marcos and the cauldron was lit by Benjamin Silva-Netto.
 The colourful opening ceremony was held in the Rizal Memorial Stadium in Manila.
 A new football stadium and indoor arena was built in Pasig named the University of Life Track & Field and Arena or the ULTRA, now called the PhilSports Arena.
 The adjacent apartments were used as the athlete's quarters and was converted into a "BLISS" housing project of First Lady Imelda Marcos.
 The final medal tally was led by Indonesia, followed by Thailand and host Philippines.
The Tulsa Coliseum was an indoor arena built in Tulsa, Oklahoma at the corner of Fifth Street and Elgin Avenue.
 Walter Whiteside, a Minnesota millionaire, constructed it in 1928.
 It hosted the Central Hockey League's Tulsa Oilers from 1945 to 1951.
 The arena held 4,502 people.
 The arena was the original home of the Tulsa Oilers ice hockey team who played their first game there on January 1, 1929 against the Duluth Hornets.
 That event not only officially opened the Coliseum, but also served as an introduction to ice hockey for the city of Tulsa.
 The facility boasted a $25,000 organ.
 Many other sporting events were held at the facility including rodeos, track meets, professional wrestling, and boxing matches.
Mexico City Arena (Spanish: "Arena Ciudad de México" ), is an indoor arena in Azcapotzalco, Mexico City, Mexico.
 It is used to host events such as concerts, sports events, and more.
 It officially opened on February 25, 2012.
 The total cost of the arena was $300 million.
 The arena has a maximum capacity of 22,300 spectators.
 It is operated by Zignia Live.
 It is located in Avenida de las Granjas, close to Metro Ferrería Station, 'Fortuna' station of the Suburban Railway and next to TecMilenio University.
The University of Nottingham operates from four campuses in Nottinghamshire and from two overseas campuses, one in Ningbo, China and the other in Semenyih, Malaysia.
 The Ningbo campus was officially opened on 23 February 2005 by the then British Deputy Prime Minister, John Prescott, in the presence of Chinese education minister Zhou Ji and State Counsellor Chen Zhili.
 The Malaysia campus was the first purpose-built UK university campus in a foreign country and was officially opened by Najib Tun Razak on 26 September 2005.
 Najib Tun Razak, as well as being a Nottingham alumnus, was Deputy Prime Minister of Malaysia at the time and has since become Prime Minister of Malaysia.
The Alytus Arena is a universal indoor arena in Alytus, Lithuania.
 It was opened in 1977.
 Its reconstruction began in 2009 and was completed by the end of 2010.
 The arena was officially opened on 12 February 2011.
 The arena hosted the Group C games of EuroBasket 2011 from 31 August 2011 to 5 September 2011.
Patrick Arena was the main sports arena located in the Greater Victoria, British Columbia, area.
 The wood constructed arena was located in the suburb municipality of Oak Bay, on the north east corner of Cadboro Bay Road and Epworth Street (then called Empress Street).
 Built in 1911 at a cost of $110,000 with a capacity for 4,000 spectators, it officially opened with public skating on December 25, 1911.
 More than 600 skaters enjoyed the thrill of opening day.
 The owners, Frank and Lester Patrick, built the arena primarily to accommodate their hockey team in the newly formed Pacific Coast Hockey Association (PCHA).
Amsterdam Arena (] , officially stylised as Amsterdam ArenA) is a stadium in Amsterdam, Netherlands.
 It is the largest stadium in the country, built from 1993 to 1996 at a cost of €140 million, and officially opened on 14 August 1996.
 It has been used for association football, American football, concerts, and other events.
 The stadium has a retractable roof combined with a grass surface.
 It has a capacity of 54,033 people during football matches, and of 68,000 people during concerts if a centre-stage setup is used (the stage in the middle of the pitch); for end-stage concerts, the capacity is 50,000, and for concerts for which the stage is located in the east side of the stadium, the capacity is 35,000.
 It held UEFA five-star stadium status, which was superseded by a new system of classification.
 From 25 October 2017, the stadium will be known as the Johan Cruijff Arena.
Rogers Place is a multi-use indoor arena in Edmonton, Alberta, Canada.
 It is mainly used for ice hockey and other indoor sports, but is also configurable as a venue for concerts or other events.
 Construction started in March 2014, and the building officially opened on September 8, 2016.
 The arena has a seating capacity of 18,347 as a hockey venue and 20,734 as a concert venue.
 It replaced Northlands Coliseum (opened 1974) as the home of the NHL's Edmonton Oilers and the WHL's Edmonton Oil Kings.
 The arena is located at the block between 101 and 104 Streets and 104 and 105 Avenues.
 Public transit access to the arena is provided by the Edmonton Light Rail Transit system (MacEwan station on the Metro Line) and Edmonton Transit Service bus.
The Sidney Myer Music Bowl is an outdoor performance venue in Melbourne, Victoria, Australia.
 It is located in the lawns and gardens of Kings Domain, Linlithgow Ave, Melbourne, close to the Arts Centre and the Southbank entertainment precinct.
 It was officially opened by Prime Minister Robert Menzies on 12 February 1959, with an audience of 30,000 people, and is listed on the Victorian Heritage Register.

Question: When was the arena, at which the first Summadayze festival was held, officially opened ?
Answer: 12 February 1959,