I got a particular postdoc position in the USA that has a start date of 1st DEC 2021. However, I would need to delay the start date for at least two weeks, it would not be possible for me join at Dec 1st. I want to join around 15-20 dec. Because i have very urgent priority work at the beginning of december (I was not aware of that before).
How common is it to delay the start of a postdoc position for a few weeks? Who is the right person to contact? And how can I convince them?