An instant win game is similar to a sweepstakes, only you don’t have to wait until a certain date to find out if you won. Instead, you find out instantly if you want a prize or not. Instant win games don’t usually require you to demonstrate any particular skill or perform a special task. They are usually free for everyone, although some do require you to obtain a code from the packaging of a product. Instant win games are always designed to promote a commercial product or service, so you should expect to be pitched somewhat during the entry process.
Prizes are generally set to be won randomly during the time of the promotion. That means a winner can happen at any time so there is no specific time which is the best time to enter. Your odds will improve the more often you enter so you should enter as often as the rules of the game permits, which could be as often as daily.