Đây là cách triển khai của tôi để tính số tuần trong JavaScript. sửa chữa cho thời gian nghỉ hè và mùa đông là tốt. Tôi đã sử dụng định nghĩa của tuần từ bài viết này: ISO 8601
Tuần là từ thứ hai đến chủ nhật, và ngày 4 tháng 1 luôn luôn trong tuần đầu tiên của năm.
// add get week prototype functions
// weeks always start from monday to sunday
// january 4th is always in the first week of the year
Date.prototype.getWeek = function () {
year = this.getFullYear();
var currentDotw = this.getWeekDay();
if (this.getMonth() == 11 && this.getDate() - currentDotw > 28) {
// if true, the week is part of next year
return this.getWeekForYear(year + 1);
}
if (this.getMonth() == 0 && this.getDate() + 6 - currentDotw < 4) {
// if true, the week is part of previous year
return this.getWeekForYear(year - 1);
}
return this.getWeekForYear(year);
}
// returns a zero based day, where monday = 0
// all weeks start with monday
Date.prototype.getWeekDay = function () {
return (this.getDay() + 6) % 7;
}
// corrected for summer/winter time
Date.prototype.getWeekForYear = function (year) {
var currentDotw = this.getWeekDay();
var fourjan = new Date(year, 0, 4);
var firstDotw = fourjan.getWeekDay();
var dayTotal = this.getDaysDifferenceCorrected(fourjan) // the difference in days between the two dates.
// correct for the days of the week
dayTotal += firstDotw; // the difference between the current date and the first monday of the first week,
dayTotal -= currentDotw; // the difference between the first monday and the current week's monday
// day total should be a multiple of 7 now
var weeknumber = dayTotal / 7 + 1; // add one since it gives a zero based week number.
return weeknumber;
}
// corrected for timezones and offset
Date.prototype.getDaysDifferenceCorrected = function (other) {
var millisecondsDifference = (this - other);
// correct for offset difference. offsets are in minutes, the difference is in milliseconds
millisecondsDifference += (other.getTimezoneOffset()- this.getTimezoneOffset()) * 60000;
// return day total. 1 day is 86400000 milliseconds, floor the value to return only full days
return Math.floor(millisecondsDifference / 86400000);
}
để thử nghiệm tôi đã sử dụng các thử nghiệm JavaScript sau trong Qunit
var runweekcompare = function(result, expected) {
equal(result, expected,'Week nr expected value: ' + expected + ' Actual value: ' + result);
}
test('first week number test', function () {
expect(5);
var temp = new Date(2016, 0, 4); // is the monday of the first week of the year
runweekcompare(temp.getWeek(), 1);
var temp = new Date(2016, 0, 4, 23, 50); // is the monday of the first week of the year
runweekcompare(temp.getWeek(), 1);
var temp = new Date(2016, 0, 10, 23, 50); // is the sunday of the first week of the year
runweekcompare(temp.getWeek(), 1);
var temp = new Date(2016, 0, 11, 23, 50); // is the second week of the year
runweekcompare(temp.getWeek(), 2);
var temp = new Date(2016, 1, 29, 23, 50); // is the 9th week of the year
runweekcompare(temp.getWeek(), 9);
});
test('first day is part of last years last week', function () {
expect(2);
var temp = new Date(2016, 0, 1, 23, 50); // is the first last week of the previous year
runweekcompare(temp.getWeek(), 53);
var temp = new Date(2011, 0, 2, 23, 50); // is the first last week of the previous year
runweekcompare(temp.getWeek(), 52);
});
test('last day is part of next years first week', function () {
var temp = new Date(2013, 11, 30); // is part of the first week of 2014
runweekcompare(temp.getWeek(), 1);
});
test('summer winter time change', function () {
expect(2);
var temp = new Date(2000, 2, 26);
runweekcompare(temp.getWeek(), 12);
var temp = new Date(2000, 2, 27);
runweekcompare(temp.getWeek(), 13);
});
test('full 20 year test', function () {
//expect(20 * 12 * 28 * 2);
for (i = 2000; i < 2020; i++) {
for (month = 0; month < 12; month++) {
for (day = 1; day < 29 ; day++) {
var temp = new Date(i, month, day);
var expectedweek = temp.getWeek();
var temp2 = new Date(i, month, day, 23, 50);
var resultweek = temp.getWeek();
equal(expectedweek, Math.round(expectedweek), 'week number whole number expected ' + Math.round(expectedweek) + ' resulted week nr ' + expectedweek);
equal(resultweek, expectedweek, 'Week nr expected value: ' + expectedweek + ' Actual value: ' + resultweek + ' for year ' + i + ' month ' + month + ' day ' + day);
}
}
}
});