Last Friday the BBC published an article about the US’ resumption of supplying military assistance to Ukraine in its defence of Russia’s invasion. But in that article, the author referenced the increased intensity of Russian drone and missile strikes on Ukraine over that week.
To show the intensity, the BBC included this graphic, which incorporates a heat map into a traditional calendar design. A thin white line separates each day and a thicker stroke separates the months.

The legend incorporates its own visualisation component, wherein the scale of the difference in the bin buckets shows. After all, there is a significant difference between a bucket of 25 strikes, say between 25 and 50, versus 250 strikes, say between 250 and 500.
I really liked this graphic a lot. It very clearly shows that increasing intensity and annotations point out the worst days for Ukraine were indeed in that last week. And in attention to detail, note how the arrows have a thin white stroke outlining them, helping create visual separation between the arrows and the calendar heatmap below.
Credit for the piece goes to the BBC graphics department.