Unix block start times should always be integer numbers of milliseconds, but aren't

[qntm]

> tai.leapSeconds.map(l => tai.atomicToUnix(l.atomic));
[ -283996800000,
  -265679999999.99997,
  -252460800000,
  -194659199999.99997,
  -189388800000,
  -181526400000,
  -168307200000,
  -157766400000,
  -152668800000.00003,
  -142128000000.00003,
  -136771200000,
  -126230400000.00002,
  -60480000000.00001,
  63072000000,
  78796800000,
  94694400000,
  126230400000,
  157766400000,
  189302400000,
  220924800000,
  252460800000,
  283996800000,
  315532800000,
  362793600000,
  394329600000,
  425865600000,
  489024000000,
  567993600000,
  631152000000,
  662688000000,
  709948800000,
  741484800000,
  773020800000,
  820454400000,
  867715200000,
  915148800000,
  1136073600000,
  1230768000000,
  1341100800000,
  1435708800000,
  1483228800000 ]

Those values should all be integers. Some kind of improper computation is going on here.

These discrepancies are significant, because if I pass in a Unix time of e.g. -265680000000 for conversion, it ends up falling on the wrong side of a boundary where the TAI/Unix offset changed, and returning an incorrect result.

Worst-case scenario, it may be necessary to pre-compute these values. Hmm.