Parents will be given two weeks notice before schools reopen, the education secretary has promised, but without giving any indication of when that might be.
Schools have been closed to the majority of children since before Christmas - apart from opening for one day in January before another government U-turn - and they're likely to remain shut for at least a month longer.
Asked on ITV's Good Morning Britain if he expects schools to open after February half-term, as had been planned when England's lockdown was announced, Mr Williamson said it will be at the "earliest" opportunity, with the government being "guided by the best scientific and health advice".
He added: "We will obviously make that decision as close to the point as possible, making sure teachers, schools, staff, pupils all have two weeks' notice in order to be able to prepare and get ready."
Earlier this week, England's Deputy Chief Medical Officer Jenny Harries suggested the government may have to take a regional approach to the reopening of schools.
Areas with the lowest prevalence of coronavirus and the least pressure on local NHS services will be told their schools can reopen first, it is understood.
Ms Harries said schoolchildren "definitely can transmit infection in schools" but added "it is not a significant driver as yet, as far as we can see, of large-scale community infections”.
On Wednesday, the Department for Education announced a recommendation to pause a daily testing regime in schools, which was designed to replace self-isolation for coronavirus contacts, over fears the scheme may not be effective due to the new variant of Covid-19.
Just five weeks ago, Mr Williamson described the scheme as a "milestone moment" in keeping schools open.
His department has made a number of U-turns throughout the pandemic, most controversially when A-level students had their exam results downgraded before Mr Williamson reversed the policy, but he's repeatedly brushed off calls to resign.
A recent exclusive ITV News poll found that '92% of teachers think he should resign'.
He was repeatedly asked on GMB if he'd offered Boris Johnson his resignation at any point during the pandemic, but refused to give a direct answer.
In response, the minister repeated this answer, or similar: "My one focus is making sure we deliver the best for our children."
Asked what it would take for him to resign, Mr Williamson simply said his job is to "deliver the very best for every children in this country" and that's what he's focused on.
With schools closed for the foreseeable future, the government has come under attack for not providing a laptop, to assist with online learning, to hundreds of thousands of children.
Speaking to Times Radio, Mr Williamson said: "In terms of laptop and tablet provision, there's already an existing stock within the school system of 2.9 million laptops and tablets.
"We're obviously topping that up, another 750,000 have already been dispatched over the last couple of weeks (and) another 50,000 this week.
"We're going to be taking that up to 1.3 million."
He said any child unable to access online learning is able to return to school - many of which are open for children of key workers.