Binning temporal data using the built-in _hours_ interval forces interval boundaries to start at midnight

Consider the following plot invocation. Every hour there’s an event and I’m trying to bin them in intervals of 11 hours each.

Plot.plot({
  color: { legend: true, transform: null },
  marks: [
    Plot.barY(
      Array.from({length: 48}, (_, i) => (new Date(2026, 7, 1 + Math.floor(i / 24), i%24))),
      Plot.binY({fill: 'count'}, {y: { interval: '11 hours'}})
    )
  ]
})

I expected each bin to be the same size (maybe expect the very last one). Instead each day is individually divided into two bins of size 11 hours and one bin of size 2 hours.

The same happens for every interval of which 24 hours isn’t an integer multiple (i.e., 5, 7, 9, …).

This might be related to https://github.com/observablehq/plot/discussions/2450

Start by reproducing the provided Plot.plot invocation and compare the 11-hour binning across the two days shown. Trace the built-in temporal interval handling used by Plot.binY; done means consecutive bins remain 11 hours wide, apart from a possible final partial bin, rather than resetting at midnight.