Right now I am taking Mandarin 1 in Brooklyn Tech. From my understanding, 号 and 日 both mean "day." I took it upon myself to check Google Translate and find out what they both mean for confirmation. I found:
号: Day of the month; number 日:Day; Date; sun
So what is the difference? Can I use both terms in one sentence?(As in I could replace one with the other) Or are they more different than similar?