Surprising jump in Scotland case counts on 2020-06-15. What was it?

[timday]

Looking at the Scotland numbers in covid-19-cases-uk.csv and there was a big spike up on 15th June e.g grep Glasgow covid-19-cases-uk.csv | tail:

2020-06-09,Scotland,S08000031,Greater Glasgow and Clyde,3990
2020-06-10,Scotland,S08000031,Greater Glasgow and Clyde,3990
2020-06-11,Scotland,S08000031,Greater Glasgow and Clyde,3995
2020-06-12,Scotland,S08000031,Greater Glasgow and Clyde,4000
2020-06-13,Scotland,S08000031,Greater Glasgow and Clyde,4004
2020-06-14,Scotland,S08000031,Greater Glasgow and Clyde,4010
2020-06-15,Scotland,S08000031,Greater Glasgow and Clyde,4805   <==== +795!
2020-06-16,Scotland,S08000031,Greater Glasgow and Clyde,4808
2020-06-17,Scotland,S08000031,Greater Glasgow and Clyde,4810
2020-06-18,Scotland,S08000031,Greater Glasgow and Clyde,4813

Seems to be true for other Scotland regions too. I don't remember/can't find anything particular in the news around then, and another Scotland tracker site at >https://www.travellingtabby.com/scotland-coronavirus-tracker/> shows no such spike (don't know where they're getting their data). It was on a Monday, but seems far too big for a "weekend rush" when the previous days were running at just a handful a day.

I note from the commit log there was something funny going on with PHS data for a few days around then.

Any ideas what it was?

[timday]

Aha... actually, in the "COVID-19 data by NHS Board: 18 June 2020" spreadsheet downloadable from https://www.gov.scot/publications/coronavirus-covid-19-trends-in-daily-data/ I find a big line across the spreadsheet and a note saying:

As of 15 June, includes people tested through the UK Government (UKG) testing programme (Regional Testing Centres, Mobile Testing Units and home testing kits). Prior to 15 June the figures show people tested through NHS labs only.
The increase on 15 June is due to the addition of all the UKG cases to the database.
For more information see notes .

So that explains it.