BBC ESL - Time prepositions

I entered BBC ESL and studied about time prepositions. Time preposition's rule is this:

At-for times of the day
On-for days and dates
In-for longer periods of time
No preposition-for some time words

I'm tried to remember its ruld and answered the quiz. I chose 7 right answer and 3 wrong answer. a quiz is this:

Dima : What did you do at the weekend?

Helen :  I had a really busy time, not like (no preposition) last

weekend when I didn't do anything at all. On Saturday, I got up at

7:30 and went to the airport to meet my aunt. In the afternoon we
                                                       for longer periods of time
went to a concert in the park. Then, in the evening we had a little
                                                  for longer periods of time
party for her. So the guests started arriving at 8ish and some were
                                       I didn't know what 'ish' means. It means 'about'->for times of the day
still there at midnight!

Dima : Sounds like you had a great time!

Helen : Yes but I'm already looking forward to (no preposition)

next weekend just so I can have a quiet time on Saturday and

Sunday!

I thought I chose all right answer. But I couldn't know about time prepositions perfectly. Now, I'm certain that I know about time prepositions perfectly!