[pontus]

You can't hand in your resignation effective at a future date. That's not how it works. If you resign, you resign. It's then up to the employer whether or not to hold you to whatever notice period is set out in your contract. Many places will not do so and release you effective immediately.

Of course, if you leave on good terms, your superiors might look at you kindly and work with you to meet not just their needs, but also your needs. That's why it pays to be humble and generous in your interactions with other people.