If you are planning an international trip – and also trying to pinch pennies – don’t fret about your airfare budget. Just plan ahead.A recent study that compares more than 900 million airfares in 3,000 international markets has identified the “prime booking windows” (the range of days that are generally cheapest to buy a ticket) for every region on the globe. The study, released by CheapAir.com, looked at all the possible days to book trips to the different areas around the world and identified which days are best to score the cheapest airfare.Canada had the shortest lead time to get the cheapest fare, with an advanced purchase date of 66 days out, while budget-conscious fliers going to the Caribbean need to plan the furthest ahead. That region’s cheapest time to buy is 207 days before a trip.Here’s a detailed breakdown of CheapAir’s results:Canada:Prime booking window: 3 weeks to about 5 months before departureBest time to buy: About 66 days from your travel dateThe average airfare: $427Cheapest month to travel: OctoberMost expensive month to travel: JulyLeast expensive days of week to fly: Tuesday and WednesdayMexico/Central America:Prime booking window: 2 weeks to almost 6 months before departureBest time to buy: About 70 days from your travel dateThe average airfare: $489Cheapest month to travel: SeptemberMost expensive month to travel: DecemberLeast expensive days of week to fly: Tuesday and WednesdayCaribbean:Prime booking window: 1 month to almost 11 months before departureBest time to buy: About 207 days from your travel dateThe average airfare: $545Cheapest month to travel: JanuaryMost expensive month to travel: DecemberLeast expensive days of week to fly: Tuesday and WednesdaySouth America:Prime booking window: 5 weeks to almost 11 months before departureBest time to buy: About 110 days from your travel dateThe average airfare: $845Cheapest month to travel: FebruaryMost expensive month to travel: DecemberLeast expensive days of week to fly: Tuesday and WednesdaySouth Pacific:Prime booking window: 54 days to just over 8 monthsBest time to buy: About 197 days from your travel dateThe average airfare: $1,708Cheapest month to travel: MayMost expensive month to travel: DecemberLeast expensive days of week to fly: Tuesday and WednesdaySign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Asia:Prime booking window: A little over a month to 7 monthsBest time to buy: About 120 days from your travel dateThe average airfare: $1,113Cheapest month to travel: NovemberMost expensive month to travel: JuneLeast expensive days of week to fly: Tuesday and WednesdayEurope:Prime booking window: About 1.5 months to a little more than 8 monthsBest time to buy: 160 days from your travel dateThe average airfare: $1,151Cheapest month to travel: MarchMost expensive month to travel: JulyLeast expensive days of week to fly: Monday, Tuesday and WednesdayAfrica/Middle East:Prime booking window: 96 to 287 days before departureBest time to buy: About 199 days from your travel dateThe average airfare: $1,238Cheapest month to travel: FebruaryMost expensive month to travel: JulyLeast expensive days of week to fly: Tuesday and WednesdayOf course, CheapAir says varying events and circumstances in each region can increase airfare to that area. For example, Oktoberfest in Munich or The Edinburgh Festival in Scotland. And don’t forget to check for flight deals and flash sales for the cheapest international fares.