Imagine if, in the old USSR, the KGB had had a single button that made history disappear...

You don't have to imagine it any more!

The UK Government's coronavirus dashboard is configured in such a way that each new day's data erases the previous day. (Can't download any more.)

So let's say for instance an Excel issue means they've scrambled to add over 15,000 missing coronavirus cases.

You can't download the old data series from before they slid the extra historical data in, to see what changed when.

Ditto when eg they change definition of "deaths".

This MUST be by design.

It would be the easiest thing in the world to assign new filenames on a daily basis, and keep older data available.

But no.

BTW, you can see this for yourself.

1. Go to any sub-page of the coronavirus stats dashboard
2. Download any CSV file
3. Hang onto it until after the daily data update
4. Go back & download it again. Bingo, it's the new data. You can't get the old again.
https://coronavirus.data.gov.uk/