It depends on your goals and preferences. Some weight training will be beneficial in any regimen as it'll help you build lean muscle mass, increase the amount of calories you burn daily, and aiding in body fat management. However, the total number of weight training days can be altered between 2-6 depending on what form of exercise you actually enjoy doing.
High Intensity Interval Training, which is also abbreviated as HIIT, is a form of cardio where you go all out for a short period of time, and then rest for a while, repeating this cycle multiple times. Numerous studies have shown that HIIT is actually far better for fat loss, and overall health, than steady state cardio. And, you can save time doing it.
Here's something else most people probably don't know: Fidgeting is good for you. It's considered a nonexercise physical activity, and it's an important way to burn energy. You get more health benefits if, in addition to exercising, you are a more fidgety, more active person the rest of the day. This means gesturing while you're talking, tapping your foot, just moving around.