Clock in the Mirror Puzzle

Joey leaves his house in the morning to go to day camp.

Just as he is leaving his house he looks at an analog clock reflected in the mirror.

There are no numbers on the clock, so Joey makes an error in reading the time since it is a mirror image. Joey assumes there is something wrong with the clock and rides his bike to day camp.

He gets there in 20 minutes and finds that just as he gets there the day camp clock has a time that is 2 1/2 hours (2 hours and 30 minutes) later than the time that he saw in the mirror image of his clock at home.

What time was it when he got to day camp?

(The clock at camp and the clock at home were both set to the correct time.)