If you're black, you should be planning for the day you quit day one as there's always cac fukkery in the cut ready to rear it's ugly head. Always keep moving.
Here's my list:
Racism. It'll rarely be overt, but when you start getting that slick shyt constantly, be out. There's no pride in being a punching bag for a check.
Emotional Burn out - If you're tired of doing the same shyt over and over, a refresh is in order.
Bawse aspirations - If your money is right, you can focus and you cant stop thinking about entrepreneurship.. jump.
Money - If you're 25+ and your money is not increasing every year or two, you need to bounce.
Suicidal Thoughts - If death is looking more appealing and you think about sweving into incoming traffic during your morning commute, quit
Time Hoe - If the job is coming home with you, interrupting your family/leisure time, quit
Emotional distress - Contrary to popular belief, dont put yourself in hell for a year to stretch out the gig in your resume and look "responsible." If the drama is too much, look for opportunities immediately.
Commute - That time adds up. If your commute is long af, throw that gig in the bushes.
Titles - If your resume be like "associate" and "assistant", it needs to be coordinator. If its coordinator, it needs to be analyst or manager. Keep rising.
Uninspiring/no challenge - You should aspire to be the best you can be. Routine, monkey work does you a big disservice. Leave if you cannot demonstrate your absolute brilliance on a daily basis.