We track our babes from day to day and then by weeks, months and years. But, when is it the best time to just rely on years to refer to a child's age? Since developmental milestones vary so much during the first stage of life, some parents continue to count by months.

This can prove a bit of a mathematical pain for people who enter conversations with them. And, beyond needing a conversion table, 37-months-old sounds a bit ridiculous.

What's your take on the numbers?