I am like bargoo- I don't have a time frame on mine, just a number. My first two mini-goals were 10 pounds each, this current mini goal, which will put me at overweight instead of obese, is 7 pounds. All of my remaining goals are 5-8 pounds each. I like having multiple smaller goals instead of a couple large goals (20 pounds, 40 pounds down, etc), it makes me feel like I'm making more progress. Plus I'm impatient, so reaching goals as quickly as possible is psychologically pleasing,
I initially had time-related goals, but I found that I'd be lazy, and then try to exercise myself to death when the goal date was getting close, which isn't a healthy way to do things!