Chestnut
This problem may not be new but I'm sure it's getting worse. Some are only just turned 4yrs which is quite young. So maybe they should start school on their 5th birthday regardless of the time of year. The school should learn to integrate them during the school year as they turn 5yrs old.
Some on here will remember that we used to do that. Three term entries based on birthdate. September, January and Easter.
For a few years as a new teacher, I had a mixed Reception/Y1 class, with Y1 who had been in for 1 or 2 or 3 terms and Reception who started at different times of the year (as above). After Easter I had 38 altogether. Teaching was interesting and TAs hadn’t been invented!
Parents were not happy if their neighbour’s ‘autumn or spring born’ child could start before their own ‘summer born’ and would produce evidence that their little genius deserved to start earlier.
When schools are now paid for bottoms on seats, it’s hard to say, “Yes we'll keep a place till January for little Alex, much less keep a place for little Alexia till April,” especially if you are an over-subscribed school.
So basically, whilst I agree with the point you make Chestnut, I wouldn’t like to go back to how it was.
In addition, there is no guarantee that the children would be any more ready to listen do and learn if the home or pre-school provision wasn’t up to much.



