ngx-bootstrap
Version:
Native Angular Bootstrap Components
70 lines • 2.38 kB
JavaScript
/**
*
* @param {number} year
* @param {number} dow - start-of-first-week
* @param {number} doy - start-of-year
* @returns {number}
*/
import { createUTCDate } from '../utils';
import { daysInYear } from './year';
import { getDayOfYear } from './day-of-year';
import { getFullYear } from '../utils/date-getters';
function firstWeekOffset(year, dow, doy) {
// first-week day -- which january is always in the first week (4 for iso, 1 for other)
var fwd = 7 + dow - doy;
// first-week day local weekday -- which local weekday is fwd
var fwdlw = (7 + createUTCDate(year, 0, fwd).getUTCDay() - dow) % 7;
return -fwdlw + fwd - 1;
}
// https://en.wikipedia.org/wiki/ISO_week_date#Calculating_a_date_given_the_year.2C_week_number_and_weekday
export function dayOfYearFromWeeks(year, week, weekday, dow, doy) {
var localWeekday = (7 + weekday - dow) % 7;
var weekOffset = firstWeekOffset(year, dow, doy);
var dayOfYear = 1 + 7 * (week - 1) + localWeekday + weekOffset;
var resYear;
var resDayOfYear;
if (dayOfYear <= 0) {
resYear = year - 1;
resDayOfYear = daysInYear(resYear) + dayOfYear;
}
else if (dayOfYear > daysInYear(year)) {
resYear = year + 1;
resDayOfYear = dayOfYear - daysInYear(year);
}
else {
resYear = year;
resDayOfYear = dayOfYear;
}
return {
year: resYear,
dayOfYear: resDayOfYear
};
}
export function weekOfYear(date, dow, doy) {
var weekOffset = firstWeekOffset(getFullYear(date), dow, doy);
var week = Math.floor((getDayOfYear(date) - weekOffset - 1) / 7) + 1;
var resWeek;
var resYear;
if (week < 1) {
resYear = getFullYear(date) - 1;
resWeek = week + weeksInYear(resYear, dow, doy);
}
else if (week > weeksInYear(getFullYear(date), dow, doy)) {
resWeek = week - weeksInYear(getFullYear(date), dow, doy);
resYear = getFullYear(date) + 1;
}
else {
resYear = getFullYear(date);
resWeek = week;
}
return {
week: resWeek,
year: resYear
};
}
export function weeksInYear(year, dow, doy) {
var weekOffset = firstWeekOffset(year, dow, doy);
var weekOffsetNext = firstWeekOffset(year + 1, dow, doy);
return (daysInYear(year) - weekOffset + weekOffsetNext) / 7;
}
//# sourceMappingURL=week-calendar-utils.js.map