I think is different in different markets, in my actual job, during the interview I said that I would need a month I’m advance to give to my old boss, to close projects and prepare my junior for my leave. After being accepted my new boss told me that this stipulation weighted a lot in the decision to hired me, because they knew I would do the same. I’m an actuarie, our jobs are kinda complex, and someone leaving the company without any notice can complicate everything a lot.