According to this website, https://www.cga.ct.gov/2000/rpt/2000-R-1188.htm, most states require a child to turn 5 before October in order to start Kindergarten. However, every time I see a redshirting discussion, the majority of the people commenting claim to live in districts with cutoffs in October or later, even though that’s not the majority of states. Is there a reason for this? What’s the cutoff in your district and if it’s after September, what percent of October children are held back?
Many people are probably reporting what the cutoff date was when they were in school (or when their kids were in school), so if the cutout changed a while ago, most people old enough to be involved in an internet discussion of the topic would still be reporting on the old dates.
"Over the last 40 years, many states have moved their kindergarten entry cutoff date to earlier in the school year. More and more states have September or August cutoffs, while fewer states have cutoffs later than October, which used to be the norm. " which confirms a shift over time, which could be biasing your sample.
Interesting to see that California in 2000 (by the link in the OP) still had a December 2 cutoff date. That was true when I was growing up in the 60s.
Observational bias and unreliable sources.
Now, I would have blamed poor sampling and fundamental methodological failure. And 4 out of 5 internet scientists that I just made up agree!
“87% of statistics and quotes on the internet are unreliable.” -Abraham Lincoln
trying to understand - does this mean a child start kindergarten when they are only 4-3/4? That seems a bit young…
Not really. In fact, I lived in CA in the 50s and started kindergarten when I was 4 years and 10 months old, graduating from high school (in another state) when I was 17. (My birthday is in late October.) I started college when I was 17, even though I had not skipped a grade. It took a couple months of school before I was as old as most of my classmates each year.
That’s pretty much exactly how old my daughter was when she started kindergarten in Ontario.
Maybe only the people that live in districts with cutoffs in October or later care enough to comment on this subject.
I’ve been telling people my whole life that I was 4 years and 11 months old when I started kindergarten, and have always been told that this was impossible. I was told that the rule was you had to be 5 years old on the first day of school. I always assumed that I just couldn’t count straight and had miscalculated somewhere.
And I was born in the 50s in California, in early October.
I’ve heard of exceptions made. I have a cousin who started 1st grade before the cutoff date, but I don’t know if she even went to kindergarten. It wasn’t required then where I lived, I don’t even know if it’s required now.
When I went to kindergarten it wouldn’t have mattered much, there was very little content, now in kindergarten they work on skills that we weren’t taught until 1st grade. Beyond kindergarten, because it starts at such a young age, the cutoff date shouldn’t matter as much as grouping students by an age difference up to one year no matter what the cutoff date.
Indiana had a cutoff some time after September 1, when I was old enough for kindergarten there, because when I went to high school there, there were kids in my class whose birthday came after the school year started-- they didn’t start high school at 14 like most of us, they started at 13. I don’t know exactly when the cutoff date was, but just going by birthdays, it was some time between Sept. 30 and Oct. 10.
My son’s birthday is Oct. 10, and he turned six shortly after starting kindergarten, because the cutoff date is now some time in June. So my son is not even the oldest kid in the class.
The start date has changed, from the day after Labor Day when I was a kid, to Aug 15 when my son started kindergarten, to now, August 5. They get a much shorter summer, but the also get the whole week of Thanksgiving, three weeks instead of two for winter, and two weeks instead of one for spring, and a fall break in October for one week. So they still go to school for the same number of weeks.
So yeah, I think people are reporting the date when they were kids, or maybe when their kids were kids. A lot of districts have changed every decade since the 1970s.
The link in the OP has Missouri’s cutoff date as July 1, but that’s no longer correct. It’s August 1 currently. I’m bummed because my daughter turns 5 next October, and I won’t be able to stop paying for day care now till 2019.
Also, you’re comparing a count of states to a count of people. Notice that in the linked list, California and New York have the December 1st cutoff. Those are two of the four most populous states; you’re looking at 4% of the states, but very nearly 20% of the US population right there.
I recall something about twins where the second on born was the first baby of the new year. I expect someday we’ll read about some parent complaining because one twin is expected to enroll a year behind the other in school, due to being born just before and after midnight… 
And the chart is not correct for NY- NYC still has a December 31 cut off date to enter kindergarten. The DOE is currently accepting applications for children born in 2013. There was a change at some point where certain school districts ( including NYC) were authorized to *mandate *kindergarten attendance for those who turn 5 before December 1st - but that wouldn’t preclude allowing those with birthdays as late as Dec 31 into the same class. This is part of the compulsory education law that generally requires those who turn six before Dec 1st to attend school beginning in the September before they turn six, while those who turn six after December 1st are not required to attend until the next September.
With my birthday in mid-September, I was technically past the cutoff date of that era. But they made an exception for me, so that I was always one of the youngest kids in each grade. But the age difference wasn’t stark, like it was when they had some kids skip a whole grade. I’m still dubious about that grade-skipping practice. My one ex, the same age as me, was skipped ahead a year in grade school, and she did not appreciate being smaller than all her classmates. When she got to college age, she took a year off to party before resuming her education (she is highly intelligent rather than a dumb party animal, but she felt like redressing the age imbalance). So we finished college at the same time.
I was born in the '50s in Ohio in mid-September. I began pre-K at the age of 3 years 11½ months. For my first 3 years of education I attended a Montessori* school, from pre-K through (the equivalent of) first grade. So when they actually made the exception for me, when I entered a school divided into regular grades, it was that I started second grade at the age of 6 years 11½ months.
*It’s different there: we didn’t sit at desks in ranks. We didn’t exactly have a syllabus either. Grade levels weren’t divided up like in standard schooling.
I was born in CA at 11:40 pm on December 2. Twenty minutes later and I would have been held back a year; as it was, I was always the youngest person in my class.
This was in the early 70s.