In 1973 I had an offer well before graduation, but luckily I turned it down for grad school. Because I missed the degree window I had been working five months before I officially got my PhD, though I had passed my exam and it was all signed off before I left for my job.
About 6-7 months after graduation from college.
Zero.
I started a (very) small business doing pipeline and field repair in my freshman year. I had to interleave work with college semesters and gradually changed to contract work in the oilfields. Prior to graduation I was earning 3 times the median income (US) and had supported myself for about 8 years. I graduated with a standing offer and went right to work. Oddly enough, it was an income reduction for me, but that was to be expected since I was starting in a new field.
This was in the early 80’s, if it matters.
I graduated in June 1997 and was hired in late December of that year. However, I had to undergo training first which means that I only started working and making enough money to fully support myself in February 1998. So, depending on the way you see it, 6 or 8 months.
I probably could have gotten a job sooner but I was picky and the typical career that awaited me after my studies didn’t appeal to me.
About 4 months after graduation IIRC. Although even though I “could” support myself on around $30k (an entry level structural engineer’s salary in the mid 90s) I opted to live with my parents as the job was with a local engineering firm 5 minutes from their house.
About a year later I changed careers to technology consulting (during the height of the dot com / Y2K tech boom) and moved to Boston.
About a year after that I opted to not have roommates anymore and moved to a small 1BR. So overall, about 2 years and change to go from bachelors degree to completely self sufficient.
It took me three months to start teaching after graduation, but three years as a subsitute teacher really didn’t make me independent (paid rent to my parents and took care of my car). My one full year of teaching was not a success (I was ‘laid off’, but could have been fired–I was not that good a teacher) and after another year of subsituting, I got a US Government job…from which I plan to retire in about 4 months after almost 35 years.