Originally posted by PaysForIt
To address weiwei_uk's question, rats mice etc only come out at night so they tend to catch more that way. As far as I know cats don't hunt more any particular time of day.

As for safety, they're far safer at night when the roads are quiet and there's fewer people and predators around.

I'll add a rider to that, we live in a relatively quiet urban area with no real cat predators and little traffic at night. In other parts of UK, let alone the world it may well be a different situation.
In Australia, many of our native animals are nocturnal therefore there is a strong onus on cat owners to keep their pets indoors at night. My Pixel is an indoors-only cat. I believe I would only let a cat outside if I rescued the cat when he was an adult who was accustomed to being outside and got too restless being indoors. I certainly wouldn't let him outside at night. Pixel is very content to stay indoors, so she won't be going outside. I believe it is much safter for her - there are many children around the neighbourhood, and some children and young adults can be quite cruel to cats.