日語 Japanese Ask Questions Thread2 質問

If you have a question about the language, ask it and fellow 4channers might see it and answer it for you.

Japanese - Ask questions thread
http://dis.4chan.org/read/lang/1174719097/l50

How do you express differences of age smaller than a year?

i.e. "A-san is 3 months older than B-san"

年上 and 年下 seem wrong somehow when talking about a difference of less than one year.