Telling thetime

I feed the cat and dog by the clock, otherwise they would keep pushing the time back and pestering me earlier and earlier.
Dog understands this and doesn’t get up until breakfast time (6am)
Cat can’t tell the time and, if I get up in the middle of the night, he starts yelling for food and keeps it up until I feed at 6. Is he particularly thick or do most cats have no sense of human time?