Forty-two may be the meaning of life but it seems six is the magic number when it comes to flying.
Research by the flight search website Skyscanner has found six weeks ahead of travel is generally the best time to book a long-haul flight.
The finding, which was gleaned from three years' of data, applies to both budget and mainstream airlines.
The Skyscanner research has also confirmed the cheapest time of year to travel, with fares for May almost 20 per cent cheaper than average.
For those who really want a bargain, the cheapest week to fly is week 19, or the week starting April 28, after the Easter school holidays.
I don't think anyone will be surprised to hear that December is the most expensive month for flights, with week 52 extracting the most from travellers' wallets.
While six weeks was found to be the overall best timing for booking long-haul flights, it can vary by destination.
Skyscanner looked at some of our favourite holiday spots and found New Zealand and Indonesia are best booked exactly six weeks out, with an average saving of 15 per cent.
Flights to Thailand are best booked five weeks out, with an average saving of 13 per cent.
Singapore is an exception, with the best savings to be found 14 weeks ahead of departure, while the UK is a surprise packet: the best deals are just one week ahead of travel, with an average saving of 11 per cent.
However, the marketing manager for Skyscanner in Australia, Dave Boyte, says waiting until the last week is a risky strategy.
"Even though some of the best fares are found closer to the travel date, it's important to remember that prices fluctuate all the time, often increasing at the very last minute," Boyte says.
Travellers who want to take the gamble may be rewarded by an airline throwing out cheap seats to fill the flight but Boyte says tracking prices for a few months ahead of your travel may be a safer bet.
If you're looking for a flight closer to home it pays to be more organised, with the best deals for short-haul flights typically found 21 weeks in advance.
Of course, bargain fares can be released at any time, so it pays to keep watch on prices if you have a particular destination in mind.
Sign up for email newsletters and alerts so you find out about sales; you can always unsubscribe after you've booked.
Some mobile apps, including Skyscanner, also allow you to 'watch' certain routes or receive an alert when a fare drops.
If you're able to be flexible in your dates and/or destination, this will nearly always result in the best prices, although you need to have been watching prices to know which fares are bargains.
Another option is to make the most of the earlybird booking season, with deals for long-haul destinations such as Europe traditionally released in waves from September through to November, for travel the following year.
Earlybirds no longer offer a guarantee of getting the cheapest deal but are still excellent value and give you the certainty of having your flights set, so you can plan other things.
Earlybird deals are particularly relevant if you're planning to join a cruise or tour and are therefore locked into dates.
Sadly, there is no magic number when it comes to the best time to book accommodation.
Getting accommodation bargains is more about going against the flow than booking on a particular date.
Weekend hotspots are often super-cheap or well-packaged during the week if you're able to get away; beach resorts in particular often struggle to fill rooms beyond Friday and Saturday nights.
Meanwhile, city hotels that make their money out of business travellers release some excellent deals for leisure travellers on weekends, often packaged with breakfast, parking and other add-ons.
Wotif (http://www.wotif.com/) product director Donna Rodios says going against the flow can also work in peak holiday periods.
"Beach accommodation can be at a premium during the school holidays, but for the same travel period you can often get great rates for CBD hotels," Rodios says.
"It can really pay to head to the cities during peak periods and take advantage of the pools, tennis courts and gyms without the crowds."
I've found one of the best ways to get a bargain on accommodation is to book a mystery hotel.
Sites offering mystery hotels or 'secret stays' give the general location and star rating of the hotel so it is not a big risk and I've discovered some great hotels that way.
Mystery deals used to be limited to capital cities - generally five-star hotels trying to fill rooms on weekends - but you can now find them for beach breaks, mountain hideaways and even outback adventures.
- Sydney Morning Herald