"X Infants' School" - apostrophe or not?

[ShrinkingViolet]

I'm not sure - either it's the school of the infants (so apostrophe), or it's an "infants school", so the infants part is an adjective rather than a noun.
Gut feeling is that "infants' " is wrong, but am not sure.
Thankfully not a school I have any dealings with, but annoying I have to drive past it at least twice a week.

Infant school?

Every other infant school I've seen is "infant school" or "infants school" but I saw a new sign outside this particular one today, and got cross, so thought I'd put it to the pedants - is it right or wrong?

It's the school belonging to more than one infant, so I'd say it's fine. Odd, but fine.

Yep, Boys'/Girls' school is correct, but no need to add the S on infant/junior school.