Best Days and Times to Book Flights: Data-Backed Analysis for 2025

For years, travel experts have repeated the same advice: "Book on Tuesday at 3pm for the cheapest flights." We analyzed 2 million flight bookings from 2024 to find out if this is actually true—and the results might surprise you.

TL;DR: The "Tuesday at 3pm" rule is mostly a myth. The best time to book depends on whether you're flying domestic or international, your destination, and your travel dates. Here's what the data actually shows.

The Methodology

We partnered with a flight data analytics firm to analyze:

• 2.1 million flight bookings from January-December 2024
• Routes covering 150+ destinations worldwide
• Both domestic US flights and international routes
• Economy class fares only (business class data coming in 2025)
• Booking-to-departure time windows from 1 day to 365 days out

Finding #1: Best Day to Book Domestic Flights

The data reveals that Sunday is consistently the cheapest day to book domestic US flights, not Tuesday.

Average Domestic Flight Prices by Booking Day

• Sunday: $347 (cheapest)
• Monday: $362
• Friday: $364
• Tuesday: $371
• Wednesday: $373
• Thursday: $378
• Saturday: $389 (most expensive)

Savings potential: Booking on Sunday vs. Saturday saves an average of $42 per ticket (12% cheaper).

Why Sunday?

Airlines tend to release sales on Friday evenings, and by Sunday, competing airlines have matched those prices. Additionally, business travelers aren't booking on Sundays, reducing demand.

Finding #2: Best Day to Book International Flights

For international flights, the pattern is different. Thursday emerged as the best day.

Average International Flight Prices by Booking Day

• Thursday: $897 (cheapest)
• Friday: $912
• Tuesday: $924
• Wednesday: $931
• Monday: $948
• Sunday: $964
• Saturday: $1,021 (most expensive)

Savings potential: Booking on Thursday vs. Saturday saves an average of $124 per ticket (12.1% cheaper).

Finding #3: Time of Day Matters (But Not How You Think)

We analyzed booking times in 3-hour windows. The results show minimal variation throughout the day, debunking the "3pm" myth.

Domestic Flights by Booking Time

• 12am-6am: $351 (cheapest, but 4% of bookings)
• 6am-9am: $364
• 9am-12pm: $368
• 12pm-3pm: $371
• 3pm-6pm: $370 (NOT the cheapest)
• 6pm-9pm: $366
• 9pm-12am: $357

Key Insight: Late night/early morning bookings are slightly cheaper ($351 vs $371 at peak), but the difference is only $20—not worth losing sleep over. The day you book matters far more than the time.

Finding #4: How Far in Advance to Book

This is where the data gets really interesting. The sweet spot varies dramatically by route type.

Domestic Flights

• 1-3 weeks out: $412 (last minute premium)
• 4-6 weeks out: $327 (sweet spot)
• 7-12 weeks out: $342
• 13-20 weeks out: $369
• 21+ weeks out: $394 (too far in advance)

Optimal booking window for domestic: 4-6 weeks before departure

International Flights

• 1-6 weeks out: $1,247 (expensive)
• 7-12 weeks out: $891 (getting better)
• 13-20 weeks out: $834 (sweet spot)
• 21-26 weeks out: $912
• 27+ weeks out: $1,038 (too far)

Optimal booking window for international: 13-20 weeks (3-5 months) before departure

Finding #5: Destination-Specific Patterns

Not all routes follow the same rules. Here's what we found for popular destinations:

Europe (Summer Travel)

• Best booking day: Tuesday
• Best advance booking: 16-22 weeks (4-5.5 months)
• Average savings: $284 vs. last-minute booking

Asia

• Best booking day: Thursday
• Best advance booking: 12-18 weeks (3-4.5 months)
• Average savings: $412 vs. last-minute booking

Caribbean/Mexico

• Best booking day: Sunday
• Best advance booking: 6-10 weeks (1.5-2.5 months)
• Average savings: $156 vs. last-minute booking

South America

• Best booking day: Thursday
• Best advance booking: 14-20 weeks (3.5-5 months)
• Average savings: $338 vs. last-minute booking

Finding #6: Seasonal Variations

The best booking day shifts based on the season you're traveling:

Summer Travel (June-August)

• Best booking day: Sunday for domestic, Tuesday for international
• Book by: March for international, May for domestic
• Why: High demand means earlier booking is essential

Fall Travel (September-November)

• Best booking day: Tuesday for both
• Book by: 6-8 weeks for domestic, 12-16 weeks for international
• Why: Shoulder season means more flexibility

Winter/Holiday Travel (December-January)

• Best booking day: Thursday (avoid weekends entirely)
• Book by: September for December travel
• Why: Holiday demand drives prices up rapidly

Spring Travel (March-May)

• Best booking day: Sunday for domestic, Thursday for international
• Book by: 4-6 weeks for domestic, 10-14 weeks for international
• Why: Moderate demand allows for later booking

Finding #7: The "Last-Minute Deal" Myth

Contrary to popular belief, last-minute deals are rare in 2025. Our data shows:

• Only 8% of flights get cheaper within 2 weeks of departure
• 92% of flights either stay the same price or increase
• Average price increase in final 2 weeks: $147 for domestic, $318 for international

Why the change? Airlines now use sophisticated AI-powered dynamic pricing. They know when seats will sell and price accordingly. The days of empty planes with desperate price cuts are mostly over.

Finding #8: Budget Carriers Follow Different Rules

Budget airlines like Spirit, Frontier, and Ryanair operate differently:

• Best booking day: Wednesday (when they release sales)
• Best booking window: 2-4 weeks out (they release inventory later)
• Price fluctuation: Higher volatility—check daily

The New Rules for 2025

Based on our analysis, here are the updated booking rules for 2025:

For Domestic US Flights

1. Book on Sunday whenever possible
2. Book 4-6 weeks before your trip
3. Set price alerts and monitor for 1-2 weeks before booking
4. Avoid booking on Saturdays (most expensive)
5. Don't wait for last-minute deals—they're rare

For International Flights

1. Book on Thursday for the best average prices
2. Book 13-20 weeks (3-5 months) in advance
3. Europe summer travel: Book by March
4. Asia travel: Book 3-4 months out
5. Set alerts the moment you know your dates

For Budget Airlines

1. Book on Wednesday (sale day)
2. Check prices daily—high volatility
3. Book 2-4 weeks out (not as far in advance)
4. Sign up for airline newsletters for flash sales

Tools to Track Prices

Don't rely on memory—use these tools to track flight prices:

Price Alert Tools

• Google Flights: Free, tracks specific routes, sends email alerts
• Hopper: AI-powered predictions with "buy now" or "wait" recommendations
• Kayak: Price alerts and price forecast
• Scott's Cheap Flights: Premium service that finds error fares and sales

How to Use Price Alerts Effectively

1. Set up alerts the moment you know your travel dates
2. Set alerts for flexible dates (±3 days)
3. Monitor for 1-2 weeks to understand the price range
4. Book when you see a price 10-15% below average
5. Don't wait for the absolute lowest price—you might miss out

Red Flags: When Prices Will Only Go Up

Certain signals indicate you should book immediately:

• Major event in destination: Olympics, World Cup, large conferences
• Limited seat availability: If flight search shows "Only 2 seats left"
• Holiday travel: Thanksgiving, Christmas, New Year's
• Peak season: Europe in summer, Caribbean in winter
• Prices creeping up: If you've tracked for 2 weeks and see consistent increases

Common Mistakes to Avoid

Mistake #1: Booking Too Early

Booking 6+ months out for domestic flights often results in higher prices. Airlines haven't released their lowest fares yet.

Mistake #2: Waiting for "The Perfect Price"

If you see a good price (10-15% below average), book it. Waiting for an extra $20-30 savings often backfires.

Mistake #3: Not Using Incognito Mode

While debated, some evidence suggests airlines track your searches. Use incognito/private browsing to avoid potential price increases.

Mistake #4: Booking Round-Trip Automatically

Sometimes two one-way tickets are cheaper than round-trip, especially mixing airlines. Always check both options.

Mistake #5: Ignoring Nearby Airports

Flying into Newark instead of JFK, or Oakland instead of SFO, can save $100-300. Check alternate airports within 50 miles.

Real Examples from Our Data

Example 1: New York to Los Angeles

• Booking 2 weeks out: $428
• Booking 5 weeks out on Sunday: $287
• Booking 15 weeks out: $342
• Savings: $141 (33%) by booking in the sweet spot

Example 2: Chicago to London

• Booking 4 weeks out: $1,247
• Booking 18 weeks out on Thursday: $783
• Booking 30 weeks out: $1,042
• Savings: $464 (37%) by booking in the sweet spot

Example 3: Miami to Cancun

• Booking 1 week out: $412
• Booking 7 weeks out on Sunday: $189
• Booking 20 weeks out: $267
• Savings: $223 (54%) by booking in the sweet spot

The Bottom Line

The old "Tuesday at 3pm" rule doesn't hold up to data scrutiny. Instead, focus on:

1. Day of Week: Sunday for domestic, Thursday for international
2. Advance Booking: 4-6 weeks for domestic, 13-20 weeks for international
3. Price Tracking: Monitor prices for 1-2 weeks before booking
4. Flexibility: Be flexible with dates and nearby airports
5. Don't Wait: Last-minute deals are rare—book when you see a good price

Following these data-backed strategies can save you $100-500 per ticket. For a family of four, that's $400-2,000 in savings—enough for a week of vacation expenses.