If I am trying to get my children into bed, and it is 8:58, and I say "get into bed, it is 9:00" They will quickly correct me that it is NOT 9:00, it is ONLY 8:58.
And yet, this same child, when asked her age will round up as much as 9 months. She just turned 10 two weeks ago. By next month she'll be telling people she is 11.