Cycling period is about a month . However, u need 3 testkits, ammonia, nitrite and nitrate, to verify that ur cycling period is over.
Ammonia will peak first and decrease significantly, then nitrite will peak and then decrease significantly , your cycling period is over when ur ammonia and nitrite register undetachable value and the nitrate show some elevated value .
it is still good to have a skimmer IMHO because it does help the system when u are slack in some tank husbandry.
IMPOSSIBLE TO CYCLE IN 1 DAY.