Jet Lag can really put a damper in your traveling. But it doesn’t have to, as long as you can make it through the first day!
The most important thing to do is to STAY AWAKE.
The secret is, once you arrive to your hotel, don’t stay there. Costa Rica has tons of fun activities so Go out! Go for a walk. Go to eat out. Check out a museum (I know this could be a sleeper in itself, but you’re still being active).
Whatever you decide to do that isn’t in your hotel room or television induced, will help you make it through the day and you can hit the sack at a decent hour. This way, when you wake up the next day you’ll be refreshed and (more or less) on local time!