why do we refer to infants above a year in months?

Question

For example we refer to infants over a year as 13 months, 16 months, 24 months, etc. Is there a reason for this convention?

In: Biology

Answer 1

When using years as a unit of time there is a level of approximation involved. So saying that they are 1 year old – they are somewhere between like 9 and 15 months. But if you use months, a 12 month old would be somewhere between 51 and 53 weeks.

When you are young you develop fast, so accurate time matters.