YOU SAID:

I have to go now, it is well past seven thirty

INTO JAPANESE

私は今行かなければなりません、それは7時半過ぎです

BACK INTO ENGLISH

I have to go now, it's past 7:30

INTO JAPANESE

私は今行かなければならない、それは7時30分を過ぎています

BACK INTO ENGLISH

I have to go now, it's past 7:30