1. Weekends (On weekends most people here don't have work or school, so it's like a small vacation.) 2. don't count (When they say a weekend doesn't "count" they mean it's not REALLY a day off/a small vacation) 3. unless you do something completely pointless. (Only if you do something "completely pointless" which means something with no goal or purpose to it. Probably something just for fun!) So, it means, a weekend is not REALLY a weekend/day off/vacation unless you do something that has no goal or something just for fun! I think that's what they're trying to say.

The sentence sounds ironic to me