I've noticed something weird over the last two years, mostly because I've been paying more attention to my colleagues' movements on LinkedIn. Many seem to take on a new job in the month of February, and many others seem to have work anniversaries in February (meaning they started their current job in the month of February).
What is special about this month? Is that when managers go on some aggressive hiring binge? Or is it because people have finished their performance review from the previous year and decided to move on?