The suspension of horse racing in Great Britain because of the coronavirus pandemic has been extended indefinitely.
York has cancelled the Dante Festival, due to run from 13 to 15 May.
The British Horseracing Authority (BHA) said it hopes to resume flat racing behind closed doors at some stage in May, if given government approval.
But spectators will not be allowed at any meetings before June, said the authority.
All fixtures had already been postponed from 18 March to 30 April.
The first four Classics of the season, including the Derby at Epsom, were postponed last week.
Organisers of the Royal Ascot meeting in June hope it can go ahead, but without spectators.
"We stopped racing in March to protect the health and safety of the public and to limit demands on the NHS," said BHA chief executive Nick Rust.
"We are in touch with government as part of our development of a responsible, coordinated plan for the return of sport when it's appropriate to do so."