paragraph_text: The two systems were to run on a trial basis for six months; early television sets supported both resolutions. However, the Baird system, which used a mechanical camera for filmed programming and Farnsworth image dissector cameras for live programming, proved too cumbersome and visually inferior, and ended with closedown (at 22:00) on Saturday 13 February 1937.

paragraph_text: On 1 July 1967, BBC Two became the first television channel in Europe to broadcast regularly in colour, using the West German PAL system that is still in use today although being gradually superseded by digital systems. (BBC One and ITV began 625-line colour broadcasts simultaneously on 15 November 1969). Unlike other terrestrial channels, BBC Two does not have soap opera or standard news programming, but a range of programmes intended to be eclectic and diverse (although if a programme has high audience ratings it is often eventually repositioned to BBC One). The different remit of BBC2 allowed its first controller, Sir David Attenborough to commission the first heavyweight documentaries and documentary series such as Civilisation, The Ascent of Man and Horizon.

paragraph_text: After a series of test transmissions and special broadcasts that began in August, regular BBC television broadcasts officially resumed on 1 October 1936, from a converted wing of Alexandra Palace in London, which housed two studios, various scenery stores, make-up areas, dressing rooms, offices, and the transmitter itself, now broadcasting on the VHF band. BBC television initially used two systems, on alternate weeks: the 240-line Baird intermediate film system and the 405-line Marconi-EMI system, each making the BBC the world's first regular high-definition television service, broadcasting Monday to Saturday from 15:00 to 16:00 and 21:00 to 22:00.

paragraph_text: Outflow channels are extremely long, wide swathes of scoured ground on Mars, commonly containing the streamlined remnants of pre-existing topography and other linear erosive features indicating sculpting by fluids moving downslope. Channels extend many hundreds of kilometers in length and are typically greater than one kilometer in width; the largest valley (Kasei Vallis) is around long, greater than wide and exceeds in depth cut into the surrounding plains. These features tend to appear fully sized at fractures in the Martian surface, either from chaos terrains or from canyon systems or other tectonically controlled, deep graben, though there are exceptions. Besides their exceptional size, the channels are also characterized by low sinuosities and high width:depth ratios compared both to other Martian valley features and to terrestrial river channels. Crater counts indicate that most of the channels were cut since the early Hesperian, though the age of the features is variable between different regions of Mars. Some outflow channels in the Amazonis and Elysium Planitiae regions have yielded ages of only tens of million years, extremely young by the standards of Martian topographic features.

paragraph_text: Radio with Pictures was an early music video program, airing on New Zealand broadcaster TV2 (later South Pacific Television) from 1976 to 1989. "RadPix" aired as a weekly, late night series featuring adult and alternative music.

paragraph_text: KPFT also broadcasts its signal live on their HD-1 channel (64k) and related alternate programming on HD-2. Notably, its HD-2 channel was home to student-run college radio station KTRU but after it signed on a new LPFM on the 96.1 frequency in southwest Houston in October 2015 (it now relies solely on internet streaming to reach listeners outside that area), KTRU abandoned the HD-2 channel of KPFT, which subsequently fell silent. The now blank HD-2 channel was soon replaced with the programming of the HD-3 channel, which was shut down. Radio Maria Hispana (Houston) the local unit of Radio Maria USA, airs Spanish-language programming for the Hispanic Catholic community on KPFT's subcarrier.

paragraph_text: Bagpuss is a British children's television series, made by Peter Firmin and Oliver Postgate through their company Smallfilms. The series of 13 episodes was first broadcast from 12 February 1974 to 7 May 1974. The title character was "a saggy, old cloth cat, baggy, and a bit loose at the seams". Although only 13 episodes were made, it remains fondly remembered, and was frequently repeated in the UK for 13 years. In 1999 "Bagpuss" topped a BBC poll for the UK's favourite children's TV programme.

paragraph_text: In Australia, it airs on Foxtel's Arena channel weekdays at 11.30 am. Episodes are six weeks behind New Zealand. Free - to - air digital channel 7TWO was airing episodes about three years behind however no longer airs episodes as of August 2015. Previous Australian broadcasters include: ABC1 2010 -- 2011, UKTV 1997 -- 2000, and SBS TV briefly between 1994 -- 1995.

paragraph_text: Yam Roll (or the long title, The Very Good Adventures of Yam Roll in Happy Kingdom) is a Canadian animated television series created by Jono Howard and Jon Izen airing on CBC Television in Canada, produced by March Entertainment. The series was first broadcast on February 6, 2006. It can be viewed on Saturday at 10:00am and 10:17am on local CBC channels as well as ABC2 (Australia) and HBO Asia.

paragraph_text: STORYFix is a television programme on United Kingdom news channel BBC News. Broadcast between May 2006 and July 2007, it was notable for presenting an alternative view of the week's news. In July 2006 it also became one of the BBC's first video podcasts.

paragraph_text: After a series of test transmissions and special broadcasts that began in August 1936, the BBC Television Service officially launched on 2 November 1936 from a converted wing of Alexandra Palace in London. ``Ally Pally ''housed two studios, various scenery stores, make - up areas, dressing rooms, offices, and the transmitter itself, which then broadcast on the VHF band. BBC television initially used two systems on alternate weeks: the 240 - line Baird intermediate film system and the 405 - line Marconi - EMI system. The use of both formats made the BBC's service the world's first regular high - definition television service; it broadcast from Monday to Saturday between 15: 00 and 16: 00, and 21: 00 and 22: 00. The first programme broadcast -- and thus the first ever, on a dedicated TV channel -- was`` Opening of the BBC Television Service'' at 15: 00. The first major outside broadcast was the coronation of King George VI and Queen Elizabeth in May 1937.

paragraph_text: It's All Geek to Me is a television program created and hosted by David Pogue that was broadcast on HD Theater and Science Channel. It first aired on May 18, 2007.

paragraph_text: Evangelische Omroep (EO, English: "Evangelical Broadcasting") is one of the twelve member-based broadcasting associations contributing to the Netherlands Public Broadcasting system. It has as its mission to bring people into contact with Jesus Christ and its statement of faith is a form of Evangelicalism. EO is one of the few broadcasting associations in the "pillarized" Dutch broadcasting system to have remained totally faithful to its religious roots. For a long time every one of its programmes made reference to God and to the Christian religion, although this is less often the case in the 21st century.

paragraph_text: The Marngrook Footy Show is a sport panel show broadcast in Australia. Debuting in 2007, the show currently airs on NITV, and was previously simulcast on Channel 31 Melbourne.

paragraph_text: History Hunters is a British television series that aired on Channel 4 from 1998 to 1999. Presented by the actor Tony Robinson, the show was a spin-off of the archaeology series "Time Team", first broadcast on Channel 4 in 1994. The series is also known as Time Team: History Hunters.

paragraph_text: Thuis () is a Belgian television soap opera, which airs on één, which is in the hands of VRT, the national broadcasting channel of the Dutch-speaking region of Belgium.

paragraph_text: Katie and Orbie is a Canadian animated television series aimed at preschoolers, originally broadcast in Canada from 1994–2002 by Family Channel and later aired in the United States on PBS from 1996–1997 and Disney Channel from 1997–2000. In Canada, the series aired uninterruptedly on Family Channel and (beginning on 2007) Disney Junior (formerly called Playhouse Disney) until December 31, 2012. The series has also aired in several countries around the world.

paragraph_text: In Latin America, the show is broadcast and subtitled by Sony Entertainment Television. In southeast Asia, it is broadcast by STAR World every Thursday and Friday nine or ten hours after. In Philippines, it is aired every Thursday and Friday nine or ten hours after its United States telecast; from 2002 to 2007 on ABC 5; 2008–11 on QTV, then GMA News TV; and since 2012 on ETC. On Philippine television history. In Australia, it is aired a few hours after the U.S. telecast. It was aired on Network Ten from 2002 to 2007 and then again in 2013, from 2008 to 2012 on Fox8, from season 13 onwards it airs on digital channel, Eleven, a sister channel to Network Ten. In the United Kingdom, episodes are aired one day after the U.S. broadcast on digital channel ITV2. As of season 12, the episodes air on 5*. It is also aired in Ireland on TV3 two days after the telecast. In Brazil and Israel, the show airs two days after its original broadcast. In the instances where the airing is delayed, the shows may sometimes be combined into one episode to summarize the results. In Italy, the twelfth season was broadcast by La3.

paragraph_text: Star Awards 2012 (Chinese: 红星大奖 2012) was a double television award ceremony held in Singapore. It is part of the annual Star Awards organised by MediaCorp for the two free-to-air channels, MediaCorp Channel 8 and MediaCorp Channel U. "Star Awards 2012" was live broadcast on Channel 8, on 22 and 29 April 2012, and the Post-Show party on Channel U after the broadcast of the second award ceremony.

paragraph_text: Sunday Feast is a British cookery show on British television channel ITV, broadcast in 2006. The show's hosts are Andi Peters and Anneka Rice. Their two resident chefs, who alternate week by week, are Ed Baines and Paul Merrett.

Question: For how long did the channel airing Bagpuss alternate different broadcasting systems?
Answer: six months