https://docs.julialang.org/en/v1/stdlib/Dates/#footnote-1
Footnote notes that in the time model used for DateTime there are no leap seconds. (Edit: LOL, just realized you were the one who posted that above!) Now, if the time model used in the generation of the data has leap seconds then yeah, you’ve got issues, provided that a leap second occurred within the bounds of your dataset, which, hopefully we’ll get rid of leapseconds and then won’t have to deal with it? From what I can see there haven’t been any since 2017 or so