• hh93@lemm.ee
    link
    fedilink
    arrow-up
    0
    ·
    1 year ago

    What would you expect “-1 month” to do for a date like 31st of March? Would the result be the same as for “-1 month” on 29th of March?

    If you go back 2 months so the 31st is existing again - should that mean that the result of using -1 month twice should be different to using -2 months?

    I think it’s just a stupid way to implement something like this as “month” isn’t a defined size so defining it with a fixed value and documenting it properly is a decent solution but noone should use that kind of function in the first place

    • ☆ Yσɠƚԋσʂ ☆@lemmygrad.ml
      link
      fedilink
      arrow-up
      2
      ·
      1 year ago

      This is literally how every sane API works in languages built by adults. For example, here’s what happens in Java:

      java.time.LocalDate.of(2023, 3, 31)
      > #object[java.time.LocalDate 0x2bc77260 "2023-03-31"]
      java.time.LocalDate.of(2023, 3, 31).minusMonths(1)
      > #object[java.time.LocalDate 0xac0dc15 "2023-02-28"]
      java.time.LocalDate.of(2023, 3, 31).minusMonths(2)
      > #object[java.time.LocalDate 0x44b9305f "2023-01-31"]
      

      I have no idea where people get this notion that a month isn’t a defined size. Do people just not understand the concept of a month?