13. Have you had breakfast yet? Yes, I had it at 8.00. Have you had breakfast yet? Yes, I had it at 8.00.

Have you had breakfast yet? Yes, I had it at 8.00. - Ты уже позавтракал? Да, я позавтракал в 8:00. (Past Simple, так как указано конкретное время в прошлом)