Ultimately, it doesn't matter where in the calendar year you put the cut-off date. Regardless of which date you choose, there will always be almost a full year between the eldest and youngest students in any grade.

Of course, it might matter to you, if you are expecting a child near the cut-off date for your region.

In Scotland there's an interesting situation like you mention where children born in Jan and Feb are able to choose which school year they start, either when they're 4.5 or 5.5. Children born from March onwards will start school the following year while those born in December or earlier will start school the previous year.

My older boy is a Jan birthday and we're dalaying him starting school till he's 5.5 for reasons that include those mentioned in TFA.

In Maryland it is a requirement to delay enrollment. Everybody born September-December has to wait until the following year.

Of course this means people born during the summer, in addition to not being able to bring cupcakes on their birthday, will now be the youngest, although not as young as the people born September-Deember would have been.

In California, if your child is born after December 1, their enrollment will be delayed until next year. However, the state is gradually pushing this date earlier and earlier in the year similar to Maryland's rules: http://www.cde.ca.gov/ci/gs/em/kinderinfo.asp

Yes, you can. In retrospect, I believe it was a good thing, but I remember in kindergarten my mom being pissed off that I'd have to wait until the next year to enroll (my bday is in dec)

The school system I went to allowed it for a friend of mine, but he was born within a few weeks of the cutoff line. It probably varies from place to place, that kind of educational decision is made at the state level or lower.