Following their tour with The Chainsmokers, the band announced on 28 November 2019 that they would be touring both the United Kingdom and Europe in 2020. The North American tour dates were later announced on 31 January 2020 with The Band Camino set to be the opening act for all shows in the US and Canada.On 5 February 2020, the band announced the release of their fourth studio album, Calm, which was released on 27 March 2020. Following the album release statement, the Australian arena tour dates, taking place between 27 November 2020 and 5 December 2020 were announced on 17 February 2020, with no confirmed support act currently. The first added Sydney show sold out within hours. Due to overwhelming demand, a second Sydney show, at the Sydney Opera House Forecourt, was added to take place on 6 December 2020. On 24 February 2020, Coin was announced as the opening act for the UK dates, All Time Low for the European dates and lovelytheband for the Latin America dates. Tickets for the North American and Australian dates were released via LiveNation, on 7 February 2020 and 21 February 2020, respectively. On 27 March 2020, the band released their fourth studio album Calm. The album was a commercial success and received generally positive reviews from critics who praised the band's artistic growth and maturity. The album charted in more than 25 countries on several charts and debuted atop the charts at number one in Australia, the UK and Scotland. The album peaked in the top ten on seventeen charts, including number two in Mexico and number four in Austria, Estonia, Ireland, New Zealand and Portugal. Prior to the official tour announcement, in June 2019 it was revealed that, as part of the tour, the band would perform as headliners for the 2020 annual Orange Warsaw Festival in Poland, originally scheduled to take place on 5 June 2020. In March 2020, it was announced that the 2020 Orange Warsaw Festival had been cancelled, due to the ongoing COVID-19 pandemic. It was subsequently announced that the European and UK leg would be postponed to 2021. On 26 June 2020, the band announced that the North America and Australian tour dates would be rescheduled to 2021 due to the COVID-19 pandemic. The band also announced additional shows in the US, UK and Europe.
