My Dad is like that too. That's why when I got offers from universities in my home town, and Universities from other cities...it's clear I didn't stay at home!
The thing is, he will always think you're going out too much. Even if you tell him you only go out once you've met deadlines etc. It's just how some parents are. Not much you can do I'm afraid.
But I was able to avoid him and his stupid rants by moving out. He eventually came up with the stupid idea of communiting 60 miles a day so that he can keep an eye on my socialising habits. Honestly, parents sometimes need to realise if their son/daughter is passing exams/assignments at University...then it shows intelligence, independence and clearly however they're deciding to spend their free time, it's healthy and contributing to success.