UK: Birthday of the Prince of Wales

The Birthday of the Prince of Wales is listed as a flag flying day by UK government guidance.

The Union Flag is specified.

https://www.gov.uk/guidance/designated-days-for-union-flag-flying

Under his Scottish title (Duke of Rothesay), the Birthday is also listed as a flag flying day by Scottish government guidance.

The Scottish Saltire is specified.

https://www.gov.scot/publications/flag-flying-on-government-buildings/