Parsing dates in Mavericks
Here are two date commands that work on Mavericks to convert/extract time from date strings:

mac:~ me$ date -j -f "%Y-%m-%d %T" "2013-10-12 09:23:28" +%s
1381584208
mac:~ me$ date -j -f "%Y/%m/%d %T" "2013/10/22 10:45:00" +%h
Oct


It's not entirely clear what you seek, but hopefully these workable examples bridge the gap for your needs.