'Within a month'

[blackshoeyellowsocks]

Don't think this belongs in Pedants' Corner but didn't warrant AIBU either so...

Could somebody clarify whether 'Within a month' would be before or after a certain date please? Eg. "We will write to you within a month of your child's birthday."

Would this be before or after my child's birthday? Sorry if I'm being a bit thick

After your child's birthday.

Thank you!

I think it could mean a month either side (i.e. allowing a total period of two months during which they might write to you).

It means anything up to a month after their birthday.

Disagree... I think it's shorthand for "within a grace period of a month either side of the birthday". I do agree that normal use would suggest that it is within a month after the birthday but strictly speaking I think the word "within" is merely stating how many days to one side or the other of the birthday date.