// |reftest| skip-if(!this.hasOwnProperty("Intl")) const timeZones = Intl.supportedValuesOf("timeZone"); assertEq(new Set(timeZones).size, timeZones.length, "No duplicates are present"); assertEqArray(timeZones, [...timeZones].sort(), "The list is sorted"); // The pattern doesn't cover the complete time zone syntax, but gives a good first approximation. const timeZoneRE = /^[a-z0-9_+-]+(\/[a-z0-9_+-]+)*$/i; for (let timeZone of timeZones) { assertEq(timeZoneRE.test(timeZone), true, `${timeZone} is ASCII`); } for (let timeZone of timeZones) { let obj = new Intl.DateTimeFormat("en", {timeZone}); assertEq(obj.resolvedOptions().timeZone, timeZone, `${timeZone} is supported by DateTimeFormat`); } if (typeof reportCompare === "function") reportCompare(true, true);