If you want to help reduce the risk of having your flight canceled when you are traveling, then avoid traveling the last couple of days of the month. Pilots are limited to the number of hours they can fly and this limit is per calendar month. On some of your more poorly-managed airlines (which is just about all of them), they can run low on available pilots right at the end of the month due to a large number being unavailable since they are maxed out on their hours for the month. This leads to increased flight cancellations due to "crew availability". Of course the airline will make it sound as if some previous flight failed to come in on time, but at the end of the month it's more likely that they just ran out of pilots. So if at all possible, try to limit your air travel at the end of the month to help avoid cancellations and the headaches that result from flight cancellations.