Longer school days, shorter summer holidays and five-term years are all options under consideration to help pupils catch up on lost learning, the education secretary has told Sky News.
"We're looking at holidays, we're looking at lengthening the school day, we're looking at a whole range of measures," he said.
Mr Williamson added that Sir Kevan Collins, an ex-teacher, government adviser and former head of the Education Endowment Foundation, has been asked to "leave no stone unturned" in coming up with plans for a catch-up programme.
"We've got to look at what is going to have the biggest positive impact on children's lives," the education secretary continued.
"That's the approach that we're taking and that's what we're looking at how we can improve the outcomes for children."