It’s hard to categorize, but here’s some indicators.
A real job makes you sweat from physical exertion for a significant part of your work day, which is at least seven hours long. Most real jobs are worked outside of heated or air conditioned spaces.
Any occupation that is primarily composed of typing and/or sitting at a desk is not a real job.
Any occupation that routinely gets you spattered head to toe, or in the face, with blood or feces is a real job.
Most real jobs pay extremely poorly, compared to aristo work. Surgery being a notable exception.
Jobs where the primary health hazards are obesity or haemorrhoids are never real jobs.
Jobs where the primary health hazards include incineration by molten metal, decapitation, joint breakdown, arch collapse, being swept overboard by anchor cables, having a limb pulled off by machinery, or starvation are almost always real jobs.
Not having to work a real job is a privilege. This privilege can be earned through merit, but more often it is achieved by luck and inheritance - one’s parents are able to afford the type of education and nutrition that makes one suitable for intellectual or pedagogical work, and one has the genetic capacity to make use of that inheritance, and one lives in a culture that has the capacity to support people who don’t work real jobs.
I’m only half kidding here. The people who hate DST are typically intelligentsia living in pricey, cultured environs and not slum-dwelling factory schlubs. I don’t think it’s people who go to bed early to save heating oil in the winter that are doing the complaining.
The point of DST is to save fuel (or, to put it in Benjamin Franklin’s terms, “to save candles”) although it also saves printers’ costs by allowing the mercantile classes to have a single set of year-round hours.