As many parts of the world commemorates the new year's eve with a lot of fireworks (which explode at the height of a take-off/landing). Are airplanes pilots required to deviate from their original route on this special day/night?
Firework displays can be a hazard to aircraft. Sufficiently large firework displays are notified to aircraft operators through NOTAMs. The Canadian NOTAM Manual contains a specific section on fireworks and pyrotechnics (Section 5.5.10). Some displays may result in the establishment of restricted airspace, which would compel aircraft to route around it. Aircraft may also choose to avoid areas in which firework displays are happening.
However as Ryathal says, fireworks are in general forbidden near airports, and airliners cruise too high to be affected by regular firework displays. The NOTAMs mentioned above are more likely to affect smaller unscheduled aircraft. There might also be occasional suspensions of operation like the Manchester one described by him.
A brochure from Manchester Airport announced windows to launch fireworks near Manchester airport in England. It’s not for New Year’s, but it states information that would be relevant for any time period:
Unfortunately, … a suspension of [airport] operations is difficult to arrange and not often possible. […] These [above-mentioned periods] are the only suspensions that will take place, so please plan your displays to fit these time periods.
Fireworks can distract pilots during critical landing and takeoff phase and their use around airports is strictly controlled.
Failure to notify a nearby airport about use of fireworks can result in up to 5 years in jail.