I have an offer to join company B but they want me to join 15May. The notice period with my company A is 1 Calendar month, so if I resign in April, I can only join Company B on 01Jun.
Company B suggests that I give my resignation notice to my employer A in April and then take vacations (I have alot of vacation days left from company A) from 15May and I start working for them (company B) during my last 2 week notice period vacations.
My question is, is this legally correct? Can I take vacations during my notice period from my current employer and start an overlapping contract (15 days overlap) with employer B ?
If your current employer agrees for you to take those holidays it shouldn't be a problem. As in that situation you don't have to work anymore for you former employer.
So yes, it's possible to take those holidays. But you have to request to take up those days formally (just like in normal circumstances).
An employer can't deny that request for any reason. If for example the company has urgent business interests (for example: if there are no employees left in that period and they can't find a replacement in the upcoming time) sometimes it's possible to deny a request. It can also depend on how important and unique your current role is. If it would take some time to onboard a new person that could factor in as well.