90 In 180 Rule

[malagabob]

Can anyone explain this rule there’s a lot of conflicting web sites.
When is the 180 day calculated from. Did it start on the day when the UK officially left the EU.
If I spent, a total of 21 days in 2022 in EU. 7 so far in 2023 and another 7 shortly. When do I calculate the 180 from. Thanks.

[wolf63]

Is this of any help?

https://www.schengenvisainfo.com/visa-calculator/

[Prudie]

It's a rolling figure so it's 180 days back from today (which I haven't worked out but must be sometime round early August 22?). Tomorrow it will be 180 days back so a day later start than today.

[bhg481]

It seems obvious to me. As soon as you step into the EU the 180 days starts. You can then only spend a total of 90 days in the EU before the 180 day deadline. As soon as you get to day 181 you can spend one more day in the EU etc; a week later you can spend 7 more days in the EU and so on.
In other words, in ANY period of 180 days you can only spend 90 in the EU.