"It is seven thirty."
時 main meaning is "time". But when following a number and pronounced ジit mean "hour of the day" (for a "lapse of X hours" it is 時間、 hour-interval): 七時半、7th hour (and) half.
BTW、 in old times the day was divised between the 12 zoodiac signs (each covering two hours). The middle of the day is then at the 6th sign. That is why AM is 午前 and PM is 午後 : before and after the zoodiacal sign of the horse.
I recently got back from Japan and whenever I hear them speak commonly they always use desu. Im assuming that for the most part if you are in Japan you wont be that familar with anyone. I mistakedly used slang from anime a few time and people will look at you sideways especially if they are older. Not because they dont really understand but the impression of . Why does he think its okay to talk to me this way. After realizing i stopped but you can only use your foreigner card for so long i think
Upside down and rotated by 180° are the same thing. The other thing is vertical mirroring, but that is not what upside down means. Upside down means "rotate by 180°". This makes sense, because it's much harder to mirror something in the real world, while turning it upside down is easy. And, as we all know, English evolved in the real world.