I am a contractor and my current contract ends on May 29. I have been in this position for a total of 3 contracts (including the current one), in contract lengths of 3 months, 3 months, and 6 months, respectively.
I am fairly sure that they will offer me an extension after this contract as I am the only one in this job position, and if I leave, they will have to find someone new to replace me.
According to my contract, I have to give a two-week notice period, however, I believe that is not enough to both find, hire and train someone new.
Given that, I would like to give a bigger notice period to my company, preferably 1 month.
How should I approach my manager about this, and would it be 'polite' to do so?
Clarification :
I plan to finish my contract which ends on May 29. What the notice period is for is me letting them know that I won't be accepting a future offer from them. (unless they give me an offer I can't refuse, which is unlikely since money is not the problem)