9, has been brought forward by a fortnight and will take place on Sept. 25, organisers announced on Monday.
The event in Doha, which serves as the traditional season opener, had previously been pushed back from its April 17 slot due to the COVID-19 pandemic.
"Due to the ongoing global health situation and ever-changing COVID-19 regulations, the 2020 Wanda Diamond League calendar remains provisional and subject to further changes," organisers said in a statement.
The competitive season is set to begin in Monaco on Aug. 14 followed by meetings in Stockholm, Lausanne, Brussels, Rome/Naples, Doha and a yet to be determined location in China.
Diamond League meetings in Eugene, London, Paris, Rabat, Gateshead and Shanghai have been cancelled. (Reporting by Arvind Sriram in Bengaluru Editing by Toby Davis)