What time of the day is the best for catching frogs?

In the morning when the sun first comes up (before it gets way too hot).

In the New York region where I live, it's best at sun-up or sun-down.

The BEST WAY to catch a turtle is to dig a 12" deep hole next to a pond (away from the water). Put a little bit of lettuce/turtle food around the hole, and more inside of the hole. Come back the next day and hopefully you'll see your new pet!