Drop 15lb with diet and exercise

I would like to drop 15lb by August. I'm doing a 1500 calorie diet along with 5-6 days of exercise. I have been doing 3-4 days of cardio(interval running) for 60minutes and then 2 days of a circuit weight training. I usually stay within my daily caloric intake but my problem is I have such long days, they usually start at 4am and end at 10pm. Because of my work schedule I don't go to the gym until 7:30pm and by the time I'm done I eat a light dinner or drink a protein shake. With this routine is it possible to drop 15lb within the time frame? Also is there any suggestions for a meal plan for such long days.

You're looking at 15 lbs in about .... 9 weeks? I think it would depend on how much you weigh right now. Either way, your goal isn't TOO far off. You could probably get it done by end of August.

As far as your meal plan I would really use personal preference and don't worry about physiological rumors about getting in your nutrients at a certain time. So in other words, if your current plan of having a protein shake at night and food during the day, works for you-- then just stick with it.

My weight now is 159lb, but I'm active. I usually run 3-4 days a week anyway. I'm just trying to shed these final pounds

I think your goal is probably on the aggressive side of things. For body composition purposes you would be better off taking things slowly but ultimately it depends on what you want to look like. If your goal is strictly to see a lower number on the scale then your training protocol and limitations would be different compared to someone who wants to look a certain way.

My assumption is that you are losing weight because you want to look lean and fit, and not because you want to see a lower number on the scale. If this is the case, you'd want to go slower (.5 to 1lb per week) and consider adding in another day of resistance training (weights).