Should a nine year old and eleven year old go to bed at the same time. at 8:30?

On a school night at 9 years old my son was told to get into bed at 8pm at 11 years old it was 9pm. I was al little more flexible on times at a weekend but then that is just my way of thinking. Everyone is different and as different beliefs in the right and wrong way to bring up their Children, there is no right or wrong (to an extent). If that time is what you are happy with and it works for you and your children stick to it.