427 Months

There's been some discussion in the office of the respective ages of my workmates young children.

One of them declared his sprog to be 12 months old.  Another announced that her kid was 25 months.

I don't get it.  Surely these children are 1 and 2 respectively.  I can understand the months thing when the kid is under a year, but after that, surely we should be referring to them with the standard unit of measurement?

No?

Well in that case, I'm 427 months old. And Dr K is getting dangerously close to 468.  Man, she's old!