Winner is Drawn from a Mail Bag
As envelopes for a mail-in sweepstakes arrive, they are sorted into bags. On the drawing date, a bag is chosen randomly. A person then reaches into that bag, pulls an envelope at random, and opens it. If the entrant has followed the sweepstakes rules, that is the winning envelope.
Conclusion: There is no way of knowing ahead of time what bag will be chosen, or which envelope will be drawn. Therefore, there is no way of predicting when to enter to win. Entry times do not matter.
Winning Entry Chosen by NumberEach entry in the sweepstakes is assigned a number in the order in which it is received. Numbers are assigned to every entry, whether it is sent online, by mail, or through another entry method. On the drawing date, a number from 1 to the last entry number is chosen by random. The entry that corresponds to that number wins. For an example of how this works, see How Does HGTV Choose Dream Home Winners?
This method of drawing winners can be used for online entries, mail-in sweepstakes, or sweepstakes with a variety of different entry methods.
Conclusion: There is no way of predicting which entry number will be chosen. Entry times do not matter.
Winning Entry Times Chosen in AdvanceMost online instant win sweepstakes choose winning times for each prize before the giveaway starts. The first person to play the game after the chosen time wins.
Although it is impossible to know which winning times will be chosen in advance, there is also another element to winning instant sweepstakes: how many people are entering at any given time.
If thousands of people are entering sweepstakes at the same time, you have to hit the winning time nearly to the second to be the winner. But during slow periods of entry, there might be several minutes after the winning time when no one enters. Thus, your window of opportunity is wider if you enter during slow times.
Conclusion: Because winning entry times are just as likely to be in the middle of the night as during the afternoon, entering when fewer people are around improves your chances. Entry times for instant win sweepstakes do matter, but only slightly. No matter how many people are entering, you still have to be lucky enough to play around the winning time.
In summary, you may have a slight edge if you enter instant win sweepstakes when fewer people are around to enter, such as late at night, on holidays, or during big events like the Super Bowl that will keep a significant number of people away from their computers during that time period. With other types of sweepstakes, the time you enter makes no difference to your chances of winning.
But remember that people do win at all times of the day. You shouldn't exhaust yourself by getting too little sleep or give up on instants altogether if you can't enter during non-peak times.