Whether you’re looking to get away for the weekend or spend a month exploring the country, booking any travel plans requires making lots of little decisions along the way that can mean the difference between big savings or bigger expenses. Even something as simple as which day of the week you book your flight can come with added costs if you’re off by a few days (or even a few hours).

With summer travel season upon us—and with fall leaf-peeping and holiday trips not too far off in the distance—it’s time you learned the right way to make all your vacation plans so you can leave your money woes at home and focus on enjoying your trip. Below is some advice that will help you figure out the best times to book your travel plans, presented by Mental Floss and Discover.

How Far in Advance to Book a Domestic Flight

There’s no shortage of studies aimed at calculating just how far in advance you should book your flight to get the best deal. But for domestic flights inside the U.S., it’s generally agreed that the best prices will likely pop up around three weeks to a month before a flight. Just don’t wait too long in the hopes of landing some magical unicorn of a deal, as that’s an easy way to miss out on getting a seat altogether.

Conversely, if you’re not one for risks or leaving details until the last minute, you can book your flight months and months in advance—just be prepared to spend a bit more (one estimate put the price difference at around $50 more for flights booked more than 200 days in advance).

How Far in Advance to Book an International Flight

If you’re looking to venture outside of the country, you’ll want to book your flight five to six months in advance to get a good deal while still pretty much guaranteeing you’ll get a seat. One prominent study gives a little leeway on these numbers, though, depending on the distance. For a flight from the U.S. to Central America, for example, you could probably get away with booking three months in advance. For South America, you can book just one month ahead and still not be financially penalized for it. Anywhere else and you’d do best to stay in that five- to six-month range.   

When to Book a Flight

If you’re looking into specific months and days to book a flight, one report pointed to January, February, and August as being the best months to score a deal on a domestic flight, especially if you book on a Tuesday (which is the best day to plan your travel during any month). If you’re an early bird (or wiling to set your alarm for savings), buying a ticket at around 5 a.m. has proven cheaper than evening prices (particularly between 8 p.m. and 11 p.m., which is reportedly the worst time to buy a plane ticket). So, going by the above advice, booking a trip early in the morning on a Tuesday during the first week of January for a flight that is around 21 days away would net you a pretty nice deal. Internationally, you’d do much of the same—booking a flight around 5 a.m. on a January morning, but you’ll want to wait until Wednesday to do it, and plan to travel in June or July.

When to Actually Fly

The day of the week you choose to fly can have a big impact on what you spend on your ticket, and one thing that most (if not all) experts and studies agree on is to avoid flying on Sundays. This is when most people will be looking to come back from a trip, so airports will be packed and flights will be booked well in advance. If possible, shoot for a Tuesday or Wednesday flight. And similar to the above, January, February, and September flights for domestic travel and April or October for international jaunts.

When to Book Your Hotel

If you’re the type of traveler who is anxious to know where you’ll be staying as far in advance as possible, this next bit of advice might make you squeamish. According to one report from a popular travel site, booking a hotel room one to three days in advance will get you the best deal, with potential savings of up to $20 a night. International stays could stretch out as long as six days. If booking a hotel at the last minute like that is cutting it a little too close for your liking, it may be better to book further in advance to ensure a room; after all, what’s $20 compared to the possibility of sleeping in your rental car? If you can swing it, plan to check into your hotel on a Sunday; this is when hotels usually clear out and there may be rooms available that they are just looking to fill.

When to Book a Rental Car

To get the best price on a rental car, you’ll want to reserve it two weeks in advance. Once you do that, make sure you’re picking the car up and dropping it off at the same place; meaning, if you’re renting your car at the airport, that’s where you’ll want to return it, too. One travel website found that the median rental price jumped from $33 to $35 per day to $65 per day once people started mixing and matching pickup and drop-off points. So pick a lane (and a location) and stick with it.

Now that you know the best time to book, here’s the best way to do it. The Discover it® Miles Card will earn you 1.5X miles for every dollar spent on purchases with no annual fee and those rewards never expire. Plus, at the end of your first year, Discover will match all the miles you’ve earned automatically, which you can put towards another awesome vacation. Visit Discover.com/Travel to learn more!