S&P fell in late 2000 and returned to that peak in in 2007.

S&P crashed in 2008 and recovered in 2013.

1 year is way too short a timeline. Maybe 5-10 years is the shortest time horizon to not be worried about market timing

EDIT: what part of this comment merited the cascade of downvotes (-5 at this moment)? You can verify the first two points fairly easily, and the last line is general advice given by many financial professionals and evidenced by the first two.