" Working extra hours can hurt team dynamics. Not everyone on the team will have the flexibility to pitch in the extra hours. Perhaps one team member has children at home whom he has to take care of. Maybe someone else has a 2-week trip planned in the upcoming months, or she has to commute a long distance and can't work as many hours. Whereas once the team jelled together and everyone worked fairly and equally, now those who work more hours have to carry the weight of those who can't or don't. The result can be bitterness or resentment between members of a formerly-happy team. "

― Edmond Lau , The Effective Engineer: How to Leverage Your Efforts In Software Engineering to Make a Disproportionate and Meaningful Impact