For those who are interested, this information has now been released and can be found on the various grammar school's websites. This is taken from The Crypt website:
https://www.cryptschool.org/admissions/how-to-apply2022 Entry (Current Year 5s)The window to register your child to sit the Entrance Test will open at noon on Monday 17th May and will be open until noon on Wednesday 30th June 2021. The Entrance Test is planned for
Saturday 11th September 2021 (when your child has started Year 6), however this will be subject to any government restrictions / guidance at the time. The School will communicate with all parents who have registered their child.