When it comes to using dates, I usually only see them being thrown onto a dimension to get some variation of a chart showing figures along a timeline. Sure, this is handy is many, many cases, but recently I learned a nifty way to use dates to recreate a calendar – and thought it was pretty cool to be honest.

Normally, we might create something like below – some measure (sales) over a time period.

What if I want to see sales within each month, at the day level? Expanding the date dimension along the columns results in a totally inflated table the extends waaaay too far right.

This is barely readable!

Instead, we take the DAY pellet and drag it onto Rows to generate a 2D calendar view of all days within each month.

With this, we can practically compare all sales for all months in 1 year on the 1 screen. So, we have a base calendar view, but’s there’s one problem. What do we put in the view? This wall of numbers is hardly great reading material.

The good news is – with this base view, we can really do a whole number of visualisations based on the comparison of days within each/different months.

Let’s look at a more useful use of the calendar view.

Do Sales Promotions Boost Sales?

We have a certain number of days throughout the year on which we’ve promoted special sales. What I’d like to check is whether the Sales figures for those days seem to be particularly high – i.e. has our promotion marketing strategy had any effect?

The first thing I want to do is get rid of all these numbers! It’s too much information. Switch the table view from Text to Shape and make it a sold square. Then I’ll drag the Sales measure onto size.

Great – now we can easily see which individual days had high sales.

Next, we want to colour the days that are promotion days. For demonstration purposes, I right-click on the date (order date) dimension, create set, and select the days which are promotion days to add to the set.

Then, I drag this new dimension onto colours. Because it’s a set – it will show up as IN/OUT.

And that’s it! We now have an easy-to-read calendar view showing promotion days and non-promotion days, clearly showing the amount of sales for all as a sized square.

What does this chart tell us? Promotion days don’t seem to benefit from higher sales than average – maybe we should rethink our marketing strategy!

With the calendar view, we can come up with a whole host of useful charts. Imagine separating weekdays from weekends and comparing sales accordingly – or the number of orders so that we can forecast our staffing schedule to match store business. Another thing we might do is go back to displaying actual sales figures but colouring them based on which days were profitable or not. The possibilities are..many.


The Data School
Author: The Data School