Months?

At what point do you no longer count a child's age in months? Lisa and I have been meeting many new people lately and they always ask "how old is that kid?" Lisa or I typically say 15 months, 15 and a half months, or 16 months (depending on when they asked and if we were rounding). Typically the men laugh that we still count in months and not years at this point. I typically blame the blog since there is a age counter, but in reality I do still count in months with or without the blog.

So back to my question, when are you supposed to stop? I know for weeks you usually stop around 8 weeks/2 months. For months, I think I am going to stop at 18 months. 1 and a half seems like a good point. I feel that there is such a difference between a 1 year old and a 1.5 year old that it is worth specifying. Now I could be wrong, but I doubt much changes from 18-24 months.

As a rationalization for counting months, I look to the methods used by child care. The child care at mother's day out has the toddlers broken out by 3 month intervals to separate all the 1 year olds so that a 13 month old and a 19 month old are not in the same class. If they do that, there must be a difference and a necessity to count in months.

At some point you also stop counting in years and switch to decades or in my mother-in-laws case, half centuries.