The_category

I have a site where I’m going to be posting 3 times a day, in the morning, afternoon and night.

i want to use the_category to show when the posts were made (they’ll be called breakfast lunch and dinner) but the posts are also categorized under other things too.

how to i exclude the other categories from showing up when i use the_category? it would be better to include the 3 categories actually, because i have a lot of other categories too.

I was thinking i could also achieve this with post formats but how would i do this? i know you can’t make your own custom post format.

and help??