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When’s the best date to go Christmas shopping?

Our HR Director Rosie asked our Data Science Director Dick Fear to use data science to figure out when the best day in December is for Christmas shopping. Here’s what Dick had to say.

Working on Trendscope has taught me that clear and intuitive data science generally works best for client facing products. So in the spirit of simplicity, I’m retiring the Christmas Equation™ in favour of a simple data driven approach. Let’s start with the question:

When is the best day in December to do your Christmas shopping?

There are lots of possible answers. But I’m going to keep it simple and suggest that the optimal day for Christmas shopping is the day when shops are least crowded and Christmas sales are most numerous. Conveniently, this definition also happens to be something I can measure using my old friend Google Trends.

For those who don’t know, Google Trends is a nifty tool for measuring the popularity over time of various search terms anywhere in the world. Therefore, if I assume that the popularity of the search term “Christmas offer” is highly correlated with the number of actual Christmas sales and offers, then the “Christmas offer” Google trend line should be informative:

Looks like the best time for Christmas offers and Christmas sales is the second week of December every year from 2013 through to 2016. But what about the crowdedness of the shops? For that lets try the search term “Christmas shopping”:


This time the yearly peak occurs during the fourth week of December, presumably because the shops get progressively more crowded right up to Christmas Eve. That’s two weeks after the Christmas offer peak, which means that according to my definition of ‘best time for Christmas shopping”, the answer is the second week of December.

Testing Testing

But I’m a data scientist at heart. So let’s do just a small amount of testing, since the search term “Christmas shopping” probably correlates with a whole load of things that may or may not include the number of people wondering around shops in London. To test this I’ve searched the terms “Westfield directions” and “Oxford Street”:

They both spike in the fourth week of December! Although shops in London get progressively busier up until the fourth week of December, Christmas offers and sales increase up until the second week, then fall off. Therefore, the best week for Christmas shopping is the second week of December.

But what about the best day? Following the same logic, there’s a clear cyclical weekly pattern to searches for Westfield and Oxford Street, which is highest over the weekend and lowest on a Wednesday or sometimes Tuesday.

And the results?

I can say with complete confidence that the best time for Christmas shopping this year is the 13th of December. With that in mind, we’ll be shutting our offices at 3pm on the 13th December to make all our Swans have enough time to get their shopping done on the best day of the year.