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// |reftest| skip-if(!this.hasOwnProperty("Intl"))
// Ensure formatRange() uses a proleptic Gregorian calendar.
let dtf = new Intl.DateTimeFormat("en", {timeZone: "UTC"});
// The Gregorian calendar was first introduced in 15 October 1582.
const firstGregorian = new Date("1582-10-15");
assertEq(dtf.formatRange(firstGregorian, firstGregorian), dtf.format(firstGregorian));
// To deal with the ten days' difference between the Julian and the Gregorian calendar, some days
// were skipped, so that 4 October 1582 was followed by 15 October 1582.
const lastJulian = new Date("1582-10-04");
assertEq(dtf.formatRange(lastJulian, lastJulian), dtf.format(lastJulian));
function rangePart(source, parts) {
return parts.filter(x => x.source === source).map(x => x.value).join("");
}
// Test with non-empty range.
assertEq(rangePart("startRange", dtf.formatRangeToParts(lastJulian, firstGregorian)),
dtf.format(lastJulian));
assertEq(rangePart("endRange", dtf.formatRangeToParts(lastJulian, firstGregorian)),
dtf.format(firstGregorian));
if (typeof reportCompare === "function")
reportCompare(0, 0);