3 ms·

or june 30th

• Someone 4y ago
  Indeed. See https://www.nist.gov/pml/time-and-frequency-division/leap-seconds-faqs https://www.nist.gov/pml/time-and-frequency-division/leap-se... And they always are end of June or December in UTC time, so locally they can happen on the first of January or first or July.