HIIT?

Hello all. I'm trying to drop 20 or so pounds and lose some body fat. I was thinking about starting HIIT. I can't go outside and run or do sprints but I can use my stationary bike or my treadmill (I'd easily prefer the bike, lol). I was thinking for now, exercising hard for about 30 - 45 seconds, then going at a slow pace for about 60 - 90 seconds, and repeat about 7 times. And then the rest of the time just go at a slightly challenging, but not too intense pace. (I plan on exercising for about 30 minutes in the morning, on an empty stomach, since that's all I have time for). As I get stronger, I'll increase the length of time to like 75 - 90 seconds of hard and 75 - 90 second of light, and make the whole workout HIIT. For now, I can only do a limited amount of HIIT...

I don't think I'll burn many calories this way, at least at first. So is it OK if I still workout in the afternoon? To see my normal afternoon workout, here's a previous topic of mine:
http://www.myfitnesspal.com/topics/show/670894-dance-dance-revolution

Does this all sound alright? Thank you!