Our PTO was accrued hourly, you'd get about 8 hours of PTO every two weeks or 80 hours.
It could be used for a day off, longer vacations or as a sick day. We also had a separate pool of Extended Sick Leave or ESL, it was accrued a bit more slowly than PTO. If you were out sick one or two days it came out of your PTO. Once you were out sick for three or more days then all of that time would be taken out of your ESL, the caveat being that you had to have a note from a doctor or otherwise prove that you were legitimately out sick.
A couple of folks were involved in bad accidents and were out for a couple of months, they were able to use up all of their ESL before reducing their PTO. We could even donate some of our PTO to someone else if they had used up all of theirs.
Up until a few years ago you could accumulate PTO indefinitely, it wasn't uncommon for people to have 8, 10 or 12 weeks accrued leave time. But that is listed as an accounts payable liability on the ledger so they reduced it to 240 hours total. If you went over that you just didn't accrue any more hours, i.e. take your time off or lose it.
We really liked the whole setup, mostly due to the flexibility. I didn't take much vacation so when I retired last year got almost a full six weeks pay in one lump sum which made a nice little boost to the bank account.
Place I used to work at had an annual limit on PTO. You could only accrue a certain amount each calendar year. However, any PTO you didn't take was paid out in full in the first pay period of January, then you started accruing again for the next year.
