A healthy rate of weight loss is 2 pounds a week at most. So in theory you could lose 16 pounds in two months if you really try, but gradual progress is important for most people to stay healthy and to keep weight off. One day at the gym most likely will not help you to lose the weight at the rate you want.
What my weekly schedule is consists of
5 times of yoga for 30-60 Mins
kickboxing an hour at the gym (about 300-500 calories)
Running a half hour 3 times a week (700 calories total)
and I do squats, pushups, and thigh work outs for about a half hour most days
Except for kickboxing, those are things you can do on non gym days
The idea is that you just need to exercise/cut out 3500 calories a week to lose a pound