forked from daren.hsu/line_push
55 lines
1.8 KiB
JavaScript
55 lines
1.8 KiB
JavaScript
function createUTCDate(year, month = 0, day = 1) {
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let date;
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if (year < 100 && year >= 0) {
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date = new Date(Date.UTC(year, month, day));
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if (isFinite(date.getUTCFullYear())) {
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date.setUTCFullYear(year);
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}
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} else {
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date = new Date(Date.UTC(year, month, day));
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}
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return date;
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}
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function firstWeekOffset(year, firstDayOfWeek, firstDayOfYear) {
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const firstWeekDayInFirstWeek = 7 + firstDayOfWeek - firstDayOfYear;
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const firstWeekDayOfYear = (7 + createUTCDate(year, 0, firstWeekDayInFirstWeek).getUTCDay() - firstDayOfWeek) % 7;
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return -firstWeekDayOfYear + firstWeekDayInFirstWeek - 1;
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}
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function dayOfYear(year, month, day, firstDayOfWeek) {
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let dayOfYear = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334][month];
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if (month > 1 && isLeapYear(year)) {
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dayOfYear++;
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}
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return dayOfYear + day;
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}
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function weeksInYear(year, firstDayOfWeek, firstDayOfYear) {
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const weekOffset = firstWeekOffset(year, firstDayOfWeek, firstDayOfYear);
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const weekOffsetNext = firstWeekOffset(year + 1, firstDayOfWeek, firstDayOfYear);
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const daysInYear = isLeapYear(year) ? 366 : 365;
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return (daysInYear - weekOffset + weekOffsetNext) / 7;
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}
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export function weekNumber(year, month, day, firstDayOfWeek, localeFirstDayOfYear) {
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const weekOffset = firstWeekOffset(year, firstDayOfWeek, localeFirstDayOfYear);
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const week = Math.ceil((dayOfYear(year, month, day, firstDayOfWeek) - weekOffset) / 7);
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if (week < 1) {
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return week + weeksInYear(year - 1, firstDayOfWeek, localeFirstDayOfYear);
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} else if (week > weeksInYear(year, firstDayOfWeek, localeFirstDayOfYear)) {
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return week - weeksInYear(year, firstDayOfWeek, localeFirstDayOfYear);
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} else {
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return week;
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}
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}
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export function isLeapYear(year) {
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return year % 4 === 0 && year % 100 !== 0 || year % 400 === 0;
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}
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//# sourceMappingURL=dateTimeUtils.js.map
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