text: // Copyright (C) 2022 Igalia, S.L. All rights reserved.
  // This code is governed by the BSD license found in the LICENSE file.
  
  /*---
  esid: sec-temporal.instant.prototype.tostring
  description: Rounding down is towards the Big Bang, not the epoch or 1 BCE
  features: [Temporal]
  ---*/
  
  const instance = new Temporal.Instant(-65_261_246_399_500_000_000n);  // -000099-12-15T12:00:00.5Z
  assert.sameValue(
    instance.toString({ smallestUnit: "second", roundingMode: "floor" }),
    "-000099-12-15T12:00:00Z",
    "Rounding down is towards the Big Bang, not the epoch or 1 BCE"
  );
  assert.sameValue(
    instance.toString({ smallestUnit: "second", roundingMode: "trunc" }),
    "-000099-12-15T12:00:00Z",
    "Rounding down is towards the Big Bang, not the epoch or 1 BCE (roundingMode trunc)"
  );
  assert.sameValue(
    instance.toString({ smallestUnit: "second", roundingMode: "ceil" }),
    "-000099-12-15T12:00:01Z",
    "Rounding up is away from the Big Bang, not the epoch or 1 BCE (roundingMode ceil)"
  );
  assert.sameValue(
    instance.toString({ smallestUnit: "second", roundingMode: "halfExpand" }),
    "-000099-12-15T12:00:01Z",
    "Rounding up is away from the Big Bang, not the epoch or 1 BCE (roundingMode halfExpand)"
  );
  