Upvote:7
That's not how it works. You get 90/180 days on a rolling basis. In other words, at any given time, you can only spend 90 out of the last 180 days inside the Schengen zone. If you've been in the Schengen zone and then spend 90 days out of the zone, you've essentially reset your clock and get another 90 days.
There's a calculator you can use to work out how many days you have at any given time.
If your nationality requires a visa to visit the Schengen area, the terms of your visa may be more restrictive than the general 90/180 day rule. If this applies, please post the details of your visa (a picture with your personal information redacted would be best), and we can take a look at that too.
Since you mention stamps, I should clarify that you will receive a new stamp every time you enter or exit the Schengen zone. The stamp shows the current date, not the date you must leave by.