Clubs outside the Premier League cannot resume training till "May 16 at the earliest" due to the coronavirus pandemic but the season can be completed in "56 days" English Football League chairman Rick Parry informed them in a letter.
The 72 clubs have been kicking their heels since the EFL suspended the campaign in the Championship, League One and Two on March 13.
All 24 sides in the Championship still had nine matches to play.
Some clubs in League One have 12 games remaining, while in League Two, teams have either nine or 10 matches remaining to complete the regular season.
However, Parry said following a EFL board meeting on Thursday they were confident once there was a resumption the league fixtures and the promotion play-offs could be completed within two months.
"The EFL Board today determined that to provide a level of certainty, clubs should not recommence any training activity with players until May 16 at the earliest," Parry wrote.
"Whenever the decision is taken that it is safe to resume, we currently estimate that the League will require 56 days approximately to complete the outstanding matches in the season (including Play-Offs)."
"As part of our contingency planning we are absolutely mindful of the need to try and mitigate the cost of this to clubs as best we can."