Disadvantages of having a physics degree & being a bit of a timekeeping nerd:

You know that most of the time when programmers are talking about UTC timestamps they actually mean UT1. (Except NTP. NTP is also developed by timekeeping nerds)

RE: https://akko.erincandescent.net/objects/874224bb-0390-4b06-9095-37e6cc6118ce

Remember: If a "second" is 1/86400th of a day, its UT1

If a "second" is "defined by taking the fixed numerical value of the caesium frequency, Δν_Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s⁻¹", its UTC/TAI.

(Dear Mastodon: Please permit the <sub> and <sup> html elements through your scrubber :()