Would it be OK to lie to the airline so that I could get home earlier?
That depends. In what context are you going to lie to them?
I'm asking for leaving my destination before the actual time.
Sometimes you have to do what you need to do to get what you want. Getting home in this case is very important.
Yeah, I have a lot to do at home and business is picking up.
If the business at home is more important than the lie to the airline, then doing the lesser evil will probably be best.