I learned a few sentences in English. That is “we’ll call it a day “. I don’t understand why the sentence has a word call. I learned that “hit me up “too. I have to go to my university (it would be better to say "I have to go to classes) every day starting next week. I don’t want to go every day. I want to go when I feel like it. So "we'll call it a day" is casual speaking which means like we are finished. A day here means the rest of the day so it means you are finished with the current job for the rest of the day. You would use "Hit me up" like if you are going to a bar and you say hit me up one, asking for a drink. It means ask for something or contact someone, like a old friend says hit me up anytime.