Finding the cheapest time to book a flight online and what days and dates are cheaper than others is important because it will save you money. For example, if you want to go on vacation but do not know when or for how long you will be travelling, booking all of your flights at once can make things more expensive as well as inconvenient. This is why I recommend researching several different airline websites (like Expedia) and looking at their various airfare deals that they offer during various times of the year before making any decisions regarding which one would best suit your travel needs. You should also look into the availability date/time of each flight that you plan on taking because some airlines like Southwest Airlines tend to have better prices (and sometimes cheaper ones) during certain weekends in particular months due to their lower demand for seats thus causing them to sell tickets at lower rates. All of this information combined with pricing tools such as Kayak’s fare predictor tool will help you determine which airline has fares that are most desirable in order to get great value out of your trip!