I've known some high level athletes...they would carb load the day before, not the day of. If anything, if you have a night game, a big lunch vs a big dinner would be an option.
When you're playing hockey or lifting heavy things, you're using glycogen for energy, which is sugar stored in the muscles. You can think of it needing to be refilled for top performance. If you have a desk job and play once a week like me, it gets refilled slowly throughout the week. If you're playing several times a week and have a physical job, you might need to pay more attention to refilling.
An easy and cheap way to do this is a big glass of chocolate milk right after a game. It's got plenty of sugar plus a little protein to help you recover. It does the job as good as most expensive shakes for a sport like hockey.
You might also want to try mixing some Gatorade in with your water. You can buy a tub of powder and put a spoonful or two in your bottle, way cheaper than buying bottles and tastes a lot better with less crap in it IMO. That's helped me in the past. You get a little supply of sugar and electrolytes through the game along with your hydration.
I say give that a shot, it will cost you maybe $5