I'm pretty sure that you heard '일곱시쯤에' . 쯤 means 'approximately' It comes right after a specific value that you are not pretty sure exactly. We can also put '정도' in place of '쯤' literal meaning of which is 'degree'
Ex) 저는 2만원 쯤 있는데요, 내일 8시 쯤에 저랑 영화 두 편 쯤 보러가요.
저는 2만원 정도 있는데요, 내일 8시 정도에 저랑 영화 두 편 정도 보러가요.
I have approximately 20 thousand won. Let's go for about 2 movies at around 8 o'clock tomorrow/
I'd recommend you to put a space before 쯤 or 정도 but sometimes it is quite flexible in terms of spacing !