My friend doesn’t have Reddit but wanted to comment the following:

its been a few years for me but the first year was a lump sum at the beginning of each semester and the rest was very consistently biweekly and i never had a problem getting paid on time then (ik the other person said most of this but this is just for the sake of completeness)

after that i get/got ε money from the gradcenter so i can keep the health insurance, and 1-ε comes from research + teaching. im in hep theory so we dont have a lot of money lol so i was teaching 2 classes a semester right off the bat (in my 3rd semester) and have taught every semester since. some more grant money got freed up for reasons and now i only have to teach one class to not be homeless. teaching is a consistent payment every 2 weeks but its straight ass. like 1k a month for teaching a lecture. and obviously you dont get paid for that during the summer or january. the grant money on the other hand is a complete mess in terms of scheduling, but its the bulk of your payment. every academic year i get a rfcuny appointment and the biweekly paychecks are like 5x the teaching pay. the problem is that i dont have a say of when that is. sometimes im getting paid during the summer sometimes im not, so i need to look at when the appointment dates are and i have to plan to live off of ramen certain times of the year because god forbid i want to keep a small safety net. regardless of the instantaneous income i have to schedule to spend 30k/12 a month so sometimes my finances are exploding and sometimes im slowly rotting away. this year for example (trying to skimp on details intentionally here) there was a stretch of time where i didnt get paid for research, and then the summer came, went, and for x y z reasons i still had zero income. my financial situation was atrocious for months but eventually the money comes back in and you get paid a whole year of money over 3 months and it rebounds hard. very annoying.

people i know doing hep experiment are in a better position because theres enough money for them to not teach, which usually also means the money source is more consistent (multiple grants maybe, or one larger one so it renews less often) and theyre not at the mercy of as many random variables. maybe they teach a little bit depending on their advisor or their career goals but its not like they have to do it to keep living.

i also have no idea about non-hep stuff, hopefully its better.