Sense of time

On the way home from Bible study, I gave up trying to explain to my four year old son why we can't go to the beach tomorrow. I explained that it's winter, and currently 29 degrees, and the water is too cold, and that we will get to see a beach in 6 months, and...he thought for a minute & replied, "Okay, so we can go in 6 days, tomorrow, because you promised." So his sense of time isn't the greatest...I'm just hoping his memory is about the same.