The Rambam, explaining that the proper character traits are those in the middle of the two extremes, applies this rule to measuring the correct amount of effort to put into gathering wealth:
One should not be greedy, desperate for wealth, nor lazy and idle from work, but content, doing a bit of work while occupying oneself in Torah; and he should be happy in that bit that is his portion.[1]
In other words, the key is to balance the two unseemly extremes of overworking and underworking. How exactly this would translate to an individual’s schedule depends on the circumstances. The Rambam incidentally gives as an example a daily schedule involving three hours of work and nine hours of learning Torah, which is a far cry from the modern standard of an eight-hour-plus workday.[2] But we also find attested a standard workday lasting from morning till evening, unless regulated by local custom.[3] Someone who, for whatever reason, needs more money will have to work longer and harder than someone who doesn’t, and so will someone who starts out with less money but has the same needs.
While the work schedule expands or limits one’s Torah learning and rest, another vital consideration is the content of one’s work. In general, people are happier doing work they enjoy even if doing so means earning less or working more. Earning a promotion at work should be viewed in this light. Sometimes the extra money promised elevates the promoted worker to the role of Chief Headache Officer, adding corresponding responsibilities and stress which, even if fairly remunerated, may be beyond what is appropriate for that worker.
But at the same time, one who declines a promotion in order to remain in the same, comfortable spot may wake up to the nightmare of a new overbearing boss hired for the role you rejected. Career decisions thus require much deliberation. The key may be to stay focused on always adding value. If you can do that, chances are good you can always find a market for your services and become your own boss, asserting your own preferences regarding work conditions.
[1] Hilchot Deot 2:7.
[2] Hilchot Talmud Torah 1:12.
[3] Bava Metzia 7:1.