nine-to-five

adjective Informal.

1. of, relating to, or during the workday, especially the hours from 9 a.m. to 5 p.m. when offices are characteristically open for business: the nine-to-five grind.
2. of, reflecting, or exhibiting a lack of willingness to work beyond the required amount of time or with more than minimal effort: With your nine-to-five mentality, you’ll never get a promotion.