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// |reftest| shell-option(--enable-temporal) skip-if(!this.hasOwnProperty("Temporal"))
// Ensure kevi'ah is correct.
//
function KeviahSymbol(year) {
let startOfYear = Temporal.PlainDate.from({
calendar: "hebrew",
year,
monthCode: "M01",
day: 1,
});
let firstDayOfPesach = Temporal.PlainDate.from({
calendar: "hebrew",
year,
monthCode: "M07",
day: 15,
});
let yearSymbol = {
353: "D", // deficient
354: "R", // regular
355: "C", // complete
383: "D", // deficient, leap year
384: "R", // regular, leap year
385: "C", // complete, leap year
};
// Week starts on Sunday.
let daySymbol = date => (date.dayOfWeek % 7) + 1;
let {daysInYear} = startOfYear;
assertEq(daysInYear in yearSymbol, true);
return `${daySymbol(startOfYear)}${yearSymbol[daysInYear]}${daySymbol(firstDayOfPesach)}`;
}
const validKeviahSymbols = new Set([
"2D3", "2C5", "2D5", "2C7",
"3R5", "3R7",
"5R7", "5C1", "5D1", "5C3",
"7D1", "7C3", "7D3", "7C5"
]);
// Modern years.
for (let year = 5700; year <= 5800; ++year) {
let sym = KeviahSymbol(year);
assertEq(validKeviahSymbols.has(sym), true, `${year} -> ${sym}`);
}
// Things start to break when year is 3760 or earlier.
// Temporal.PlainDate.from({calendar:"hebrew", year:3760, monthCode:"M01", day:1}).withCalendar("iso8601").year == -1
//
// Temporal.PlainDate.from({calendar:"hebrew", year:3760, monthCode:"M01", day:1}).dayOfWeek returns 7 (Sunday), but should be 6 (Saturday).
//
if (typeof reportCompare === "function")
reportCompare(true, true);