There had been hopes that a likely 12-event schedule would be made public, offering clarity and potential for greater logistical planning ahead of next season.
The delay has been caused by the events and the promoter still working through the finer details of contracts for next season. Roughly half the rallies involved in next year have signed with the promoter.
One source said: "It's unfortunate that we're not going to have the calendar, it would have helped to give us clarity for next year, but if the events aren't signed up, what's the point in issuing something.
"What we need to make sure is that we do have something in a month."
The calendar was the source of much speculation in Sardinia last week, where Jean Todt met with Automobile Club Italy officials to discuss the country's WRC future.
Italy and Greece are being touted as the two events most likely to be dropped next year, in favour of a 12-event schedule and Poland, China or Brazil coming in.