I would like to get the first day of a week in a given year (assuming the week starts on a Monday).
Scenario: The year is 2016. It should return 4, because Monday the 4th of January 2016 is the first day of week 1 in 2016.
How would I do that? I want something like this:
var date = new Date();
var week = 1;
var year = 2016;
date.getMonday(week, year); // 4 (because 04/01/2016 is a Monday and is week number 1)
week = 5;
date.getMonday(week, year); // 30 (because 30/01/2016 is a Monday and is week number 5)
Thanks
You can use JavaScript's getDay() method to figure out which day of the week a date object refers to.
var output = document.getElementById('output');
var year = 2016;
var firstMonday = new Date(year, 0, 1); // year, month (zero-index), date
// starting at January 1st, increment the date until a Monday (`getDay() = 1`)
while(firstMonday.getDay() !== 1) {
firstMonday.setDate(firstMonday.getDate() + 1);
}
// output the date of the first Monday in January
output.value = firstMonday.getDate();
<textarea id="output"></textarea>
I've made a function to solve this... see bellow
function getDayInWeek(dayOfWeek, week, year){
dayOfWeek = dayOfWeek % 7; //ensure day of week
var baseDate = new Date(year, 0, 1); //get the first day
var firstDayOfWeek = baseDate.getDay(); //get the first week day
var inWeek = (week - 1) * 7; //get the days to start of week
var diff = firstDayOfWeek - dayOfWeek; //get the diff for day in that week
if(diff < 0) diff += 7;
baseDate.setDate(inWeek + diff);
return baseDate.getDate(); //get the month day
}
to use specify the week day
// 0 = sunday
// 1 = monday
// 2 = tuesday
// 3 = wednesday
// 4 = thursday
// 5 = friday
// 6 = saturday
var firstMonday = getDayInWeek(1, 1, 2016); // the monday in first week of 2016
var mondayOf5 = getDayInWeek(1, 5, 2016); // the monday in 5th week of 2016
To get ISO-8601 week, which will always be a Monday, see link:
Wikipedia
Calculate ISO 8601
function getISOWeek(week, year) {
var _date = new Date(year, 0, 1 + (week - 1) * 7);
var date_of_week = _date.getDay();
var ISOweekStart = _date;
(date_of_week <= 4) ? ISOweekStart.setDate(_date.getDate() - _date.getDay() + 1): ISOweekStart.setDate(_date.getDate() + 8 - _date.getDay());
return ISOweekStart;
}
console.log(getISOWeek(10, 2016));
Related
I thought a lot - I tried but I could not solve it. I need a JavaScript application that shows the nearest weekend dates in the current date.
If it's a weekend now, give it the dates of this weekend, if not, then next weekend's dates.
I'm waiting for your help.
Respects.
You can use the built-in Date constructor.
var date = new Date();
var day = date.getDay();
var saturday;
var sunday;
if(day === 0 || day === 6){ //0 for Sunday, 6 for Saturday
saturday = date;
sunday = new Date(saturday.getTime());
sunday.setDate(saturday.getDate() + (day === 0 ? -1 : 1));
if(day === 0){
var temp = saturday;
saturday = sunday; //Confusing, but they are actually the wrong dates, so we are switching the dates
sunday = temp;
temp = null; //Free up some memory!
}
}
else{
//This is the complicated part, we need to find when is the next Saturday
saturday = new Date(date.getFullYear(), date.getMonth(), (date.getDate() + 6) - day);
sunday = new Date(saturday.getTime());
sunday.setDate(saturday.getDate() + (saturday.getDay() === 0 ? -1 : 1));
}
date = day = null; //Free up some memory!
document.body.innerText = [saturday, sunday];
To get the date, use saturday.getDate() or sunday.getDate().Remember that Date months are 0-based. See here for more info.
var chosenDay = new Date();
var box = [];
var counting = 0;
for (var i = 0; i < 7; i++) {
chosenDay.setDate(chosenDay.getDate() + counting);
var day = chosenDay.getDate();
var dayy = chosenDay.getDay();
var month = chosenDay.getMonth()+1;
var year = chosenDay.getFullYear();
box.push({day: day, dayy: dayy});
counting = 1;
};
Now to find Saturday and Sunday
box.map(function(obj) {
if (obj.dayy === 6) {
console.log('Saturday found');
alert(obj.day);
};
if (obj.dayy === 0) {
console.log('Sunday found');
alert(obj.day);
};
});
I interpret the "nearest" weekend as being the previous weekend for Monday and Tuesday, and the next weekend for Thursday and Friday. You didn't provide any information on what to do with Wednesday.
However, from other answers it seems you want either the current weekend for Saturday and Sunday and or the next weekend for weekdays.
The following is a little more concise than other answers:
/* Get nearest weekend to the provided date
** #param {Date} date - date to get weekends nearst to
** #returns {Array} array of Dates [Saturday, Sunday]
*/
function getNearestWeekend(date) {
// Copy date so don't mess with provided date
var d = new Date(+date);
// If weekday, move d to next Saturday else to current weekend Saturday
if (d.getDay() % 6) {
d.setDate(d.getDate() + 6 - d.getDay());
} else {
d.setDate(d.getDate() - (d.getDay()? 0 : 1));
}
// Return array with Dates for Saturday, Sunday
return [new Date(d), new Date(d.setDate(d.getDate() + 1))]
}
// Some tests
[new Date(2017,0,7), // Sat 7 Jan
new Date(2017,0,8), // Sun 8 Jan
new Date(2017,0,9), // Mon 9 Jan
new Date(2017,0,12) // Thu 12 Jan
].forEach(function(d) {
var opts = {weekday:'short', day:'numeric', month:'short'};
console.log('Date: ' + d.toLocaleString('en-GB',opts) + ' | Next weekend: ' +
getNearestWeekend(d).map(d =>d.toLocaleString('en-GB',opts)).join(' and ')
);
});
Moment js has a function to get the number of days in a month : http://momentjs.com/docs/#/displaying/days-in-month/
However I could not find a function to find the number of iso weeks in a year (52 or 53).
Here's an answer that isn't dependent on a library. It uses a function to calculate the week in the year that 31 December falls in for the required year. If the week is 1 (i.e. 31 December is in the first week of the following year), it moves the day number lower until it gets a different value, which will be the last week of the required year.
function getWeekNumber(d) {
// Copy date so don't modify original
d = new Date(+d);
d.setHours(0, 0, 0, 0);
// Set to nearest Thursday: current date + 4 - current day number
// Make Sunday's day number 7
d.setDate(d.getDate() + 4 - (d.getDay() || 7));
// Get first day of year
var yearStart = new Date(d.getFullYear(), 0, 1);
// Calculate full weeks to nearest Thursday
var weekNo = Math.ceil((((d - yearStart) / 86400000) + 1) / 7)
// Return array of year and week number
return [d.getFullYear(), weekNo];
}
function weeksInYear(year) {
var month = 11,
day = 31,
week;
// Find week that 31 Dec is in. If is first week, reduce date until
// get previous week.
do {
d = new Date(year, month, day--);
week = getWeekNumber(d)[1];
} while (week == 1);
return week;
}
[2015, 2016, 2029, new Date().getFullYear()].forEach(year =>
console.log(`${year} has ${weeksInYear(year)} weeks`)
);
The getWeekNumber code is from here: Get week of year in JavaScript like in PHP.
Edit
Alternatively, if 31 December is in week 1 of the following year, then the subject year has 52 weeks and otherwise has 53 weeks.
function getWeekNumber(d) {
d = new Date(+d);
d.setHours(0, 0, 0, 0);
d.setDate(d.getDate() + 4 - (d.getDay() || 7));
var yearStart = new Date(d.getFullYear(), 0, 1);
var weekNo = Math.ceil((((d - yearStart) / 86400000) + 1) / 7)
return [d.getFullYear(), weekNo];
}
function weeksInYear(year) {
var d = new Date(year, 11, 31);
var week = getWeekNumber(d)[1];
return week == 1 ? 52 : week;
}
[2015, 2016, 2029, new Date().getFullYear()].forEach(year =>
console.log(`${year} has ${weeksInYear(year)} weeks`)
);
Use isoWeek on the last day of the year to get the number of weeks e.g. :
function weeksInYear(year) {
return Math.max(
moment(new Date(year, 11, 31)).isoWeek()
, moment(new Date(year, 11, 31-7)).isoWeek()
);
}
Feb. 4th 2014 the weeksInYear & isoWeeksInYear functions were added to moment.js
So today you can just use moment().isoWeeksInYear()or moment().weeksInYear()
For more into see the docs
Thought I would post a much simpler version that I derived from the wikipedia article.
https://en.wikipedia.org/wiki/ISO_week_date
The statement in the article is:
"The number of weeks in a given year is equal to the corresponding
week number of 28 December, because it is the only date that is always
in the last week of the year since it is a week before 4 January which
is always in the first week of the following year.
Using only the ordinal year number y, the number of weeks in that year
can be determined from a function, that
returns the day of the week of 31 December"
Therefore getWeekFor(new Date(2022, 11, 28) replacing the year with any year you want will always give you the number of weeks for that year.
// modified from https://stackoverflow.com/questions/6117814/get-week-of-year-in-javascript-like-in-php
const getWeekFor = (date) => {
const d = new Date(Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()));
const dayNum = d.getUTCDay() || 7;
const utc = new Date(d.setUTCDate(d.getUTCDate() + 4 - dayNum));
const yearStart = new Date(Date.UTC(utc.getUTCFullYear(), 0, 1)).getTime();
return Math.ceil(((d.getTime() - yearStart) / 86400000 + 1) / 7);
};
const weeks = getWeekFor(new Date(2020, 11, 28)) // 53.
console.log(weeks);
Get all weeks and periods of that week for a year, for whom it may interest
function getWeekPeriodsInYear(year) {
weeks = [];
// Get the first and last day of the year
currentDay = moment([year, 1]).startOf('year');
dayOfWeek = moment(currentDay).day();
lastDay = moment([year, 1]).endOf('year');
weeksInYear = moment(`${year}-01-01`).isoWeeksInYear();
daysToAdd = 7 - dayOfWeek;
for (let weekNumber = 1; weekNumber < weeksInYear + 1; weekNumber++) {
let endOfWeek = moment(currentDay).add(daysToAdd, 'days');
if (moment(endOfWeek).year() !== year) {
endOfWeek = lastDay;
}
weeks.push({ weekNumber, start: currentDay.toDate(), end: endOfWeek.toDate() });
currentDay = endOfWeek.add(1, 'day');
daysToAdd = 6;
}
return weeks;
}
getWeekPeriodsInYear(new Date().getFullYear()).forEach(period =>
document.write(`Week ${period.weekNumber} from ${moment(period.start).format('DD-MM-YYYY')} up to and including ${moment(period.end).format('DD-MM-YYYY')}<br/>`)
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>
I am using the following script to get Monday (first) and Sunday (last) for the previous week:
var curr = new Date; // get current date
var first = curr.getDate() - curr.getDay() - 6; // Gets day of the month (e.g. 21) - the day of the week (e.g. wednesday = 3) = Sunday (18th) - 6
var last = first + 6; // last day is the first day + 6
var startDate = new Date(curr.setDate(first));
var endDate = new Date(curr.setDate(last));
This works fine if last Monday and Sunday were also in the same month, but I just noticed today that it doesn't work if today is December and last Monday was in November.
I'm a total JS novice, is there another way to get these dates?
You can get the previous Monday by getting the Monday of this week and subtracting 7 days. The Sunday will be one day before that, so:
var d = new Date();
// set to Monday of this week
d.setDate(d.getDate() - (d.getDay() + 6) % 7);
// set to previous Monday
d.setDate(d.getDate() - 7);
// create new date of day before
var sunday = new Date(d.getFullYear(), d.getMonth(), d.getDate() - 1);
For 2012-12-03 I get:
Mon 26 Nov 2012
Sun 25 Nov 2012
Is that what you want?
// Or new date for the following Sunday
var sunday = new Date(d.getFullYear(), d.getMonth(), d.getDate() + 6);
which gives
Sun 02 Dec 2012
In general, you can manipulate date objects by add and subtracting years, months and days. The object will handle negative values automatically, e.g.
var d = new Date(2012,11,0)
Will create a date for 2012-11-30 (noting that months are zero based so 11 is December). Also:
d.setMonth(d.getMonth() - 1); // 2012-10-30
d.setDate(d.getDate() - 30); // 2012-09-30
if you dont want to do it with an external library you should work with timestamps. i created a solution where you would substract 60*60*24*7*1000 (which is 604800000, which is 1 week in milliseconds) from the current Date and go from there:
var beforeOneWeek = new Date(new Date().getTime() - 60 * 60 * 24 * 7 * 1000)
, day = beforeOneWeek.getDay()
, diffToMonday = beforeOneWeek.getDate() - day + (day === 0 ? -6 : 1)
, lastMonday = new Date(beforeOneWeek.setDate(diffToMonday))
, lastSunday = new Date(beforeOneWeek.setDate(diffToMonday + 6));
You could use a library like moment.js.
See the subtract method http://momentjs.com/docs/#/manipulating/subtract/
A few answers mentioned moment, but no one wrote about this simple method:
moment().day(-13) // Monday last week
moment().day(-7) // Sunday last week
.day sets a week day, so it doesn't matter what day is it today, only week matters.
This is the general solution of find any day of any week.
function getParticularDayTimestamp(lastWeekDay) {
var currentWeekMonday = new Date().getDate() - new Date().getDay() + 1;
return new Date().setDate(currentWeekMonday - lastWeekDay);
}
console.log(getParticularDayTimestamp(7)) // for last week monday
console.log(getParticularDayTimestamp(1)) // for last week sunday
console.log(getParticularDayTimestamp(14)) // for last to last week monday
console.log(getParticularDayTimestamp(8)) // for last to last week sunday
Using Moment you can do the following
var lastWeek = moment().isoWeek(moment().subtract(1,'w').week());
var mondayDifference = lastWeek.dayOfYear() - lastWeek.weekday() + 1;
var sundayDifference = mondayDifference - 1;
var lastMonday = moment().dayOfYear(mondayDifference);
var lastSunday = moment().dayOfYear(sundayDifference );
it can be this simple.
var today = new Date();
var sunday = new Date(this.today.getFullYear(), this.today.getMonth(), this.today.getDate() - this.today.getDay());
Here you have a multi-purpose function:
function getThe(numOfWeeks, weekday, tense, fromDate) {
// for instance: var lastMonday = getThe(1,"Monday","before",new Date())
var targetWeekday = -1;
var dateAdjustment = clone(fromDate);
var result = clone(fromDate);
switch (weekday) {
case "Monday": targetWeekday = 8; break;
case "Tuesday": targetWeekday = 2; break;
case "Wednesday": targetWeekday = 3; break;
case "Thursday": targetWeekday = 4; break;
case "Friday": targetWeekday = 5; break;
case "Saturday": targetWeekday = 6; break;
case "Sunday": targetWeekday = 7;
}
var adjustment = 7 * (numOfWeeks - 1);
if (tense == "after") adjustment = -7 * numOfWeeks;
dateAdjustment.setDate(fromDate.getDate() - targetWeekday);
var weekday = dateAdjustment.getDay();
result.setDate(fromDate.getDate() - weekday - adjustment);
result.setHours(0,0,0,0);
return result;
}
You can find the "clone(obj)" function in the next post: https://stackoverflow.com/a/728694/6751764
You can use a third party date library to deal with dates. For example:
var startOfWeek = moment().startOf('week').toDate();
var endOfWeek = moment().endOf('week').toDate();
if you want to use JavaScript then use the below code
var curr = new Date; // get current date
var first = curr.getDate() - curr.getDay()+1; // First day is the day of the month - the day of the week
var last = first + 6; // last day is the first day + 6
var startDate = new Date(curr.setDate(first));
startDate = ""+startDate.getFullYear()+"-"+ (startDate.getMonth() + 1) + "-" + startDate.getDate()
var endDate = new Date(curr.setDate(last));
endDate = "" + (endDate.getMonth() + 1) + "/" + endDate.getDate() + "/" + endDate.getFullYear();
alert(startDate+" , "+endDate)
i'm looking for a simple way to calculate the calendar days when given a week and year number using jquery/javascript.
Example: Week 18, Year 2012 would result in a list of starting with sunday
2012-04-29
2012-04-30
2012-05-01
2012-05-02
2012-05-03
2012-05-04
2012-05-05
thanks
If you remake the code from this question you will get something like this:
function getDays(year, week) {
var j10 = new Date(year, 0, 10, 12, 0, 0),
j4 = new Date(year, 0, 4, 12, 0, 0),
mon = j4.getTime() - j10.getDay() * 86400000,
result = [];
for (var i = -1; i < 6; i++) {
result.push(new Date(mon + ((week - 1) * 7 + i) * 86400000));
}
return result;
}
DEMO: http://jsfiddle.net/TtmPt/
You need to decide what day begins a week - you specified Sunday. (ISO weeks start on Monday).
Get the day of the week of Jan 1.
Get the date of the closest Sunday.
If Jan 1 is on a Thursday, Friday, Saturday or Sunday, the first week of the year begins a week from the last Sunday in December. Otherwise, the first week of the year begins on the last Sunday of December.
Find the first day of any week of the year by setting the date to the first day + (weeks * 7) - 7.
var year= new Date().getFullYear(),
firstDay= new Date(year, 0, 1),
wd= firstDay.getDay();
firstDay.setDate(1 +(-1*(wd%7)));
if(wd>3){
firstDay.setDate(firstDay.getDate()+ 7);
}
var week4= new Date(firstDay);
week4.setDate(week4.getDate()+(4*7)- 7);
alert(week4);
returned value:(Date)
Sun Jan 20 2013 00: 00: 00 GMT-0500(Eastern Standard Time)
jquery/javascript- calculate days on this week given week number and year number
var years = $('#yr').val();
var weeks = $('#weekNo').val();
var d = new Date(years, 0, 1);
var dayNum = d.getDay();
var diff = --weeks * 7;
if (!dayNum || dayNum > 4) {
diff += 7;
}
d.setDate(d.getDate() - d.getDay() + ++diff);
$('#result').val(d);
[Demo] [1]: https://jsfiddle.net/2bhLw084/
what would be a way in javascript to detect the last week of each (current) month. Or last monday of the month?
I would suggest to get the number of days in the month and then loop from the last day until getDay() gives back a Monday (1) or Sunday(0) .. based on when does your week start. Once you get your start date ... end date would be startDate + 7 so something along these lines
I found this helpful :
//Create a function that determines how many days in a month
//NOTE: iMonth is zero-based .. Jan is 0, Feb is 2 and so on ...
function daysInMonth(iMonth, iYear)
{
return 32 - new Date(iYear, iMonth, 32).getDate();
}
Then the loop:
//May - should return 31
var days_in_month = daysInMonth(4, 2010);
var weekStartDate = null;
var weekEndDate = null;
for(var i=days_in_month; i>0; i--)
{
var tmpDate = new Date(2010, 4, i);
//week starting on sunday
if(tmpDate.getDay() == 0)
{
weekStartDate = new Date(tmpDate);
weekEndDate = new Date(tmpDate.setDate(tmpDate.getDate() + 6));
//break out of the loop
break;
}
}
Playing with the date object and its methods you can do the following..
update
the complete calculations to get to last monday of the month could be compacted to
var d = new Date();
d.setMonth( d.getMonth() + 1 );
d.setDate(0);
lastmonday = d.getDate() - (d.getDay() - 1);
alert(lastmonday);
verbose example..
var now = new Date(); // get the current date
// calculate the last day of the month
if (now.getMonth() == 11 ) // if month is dec then go to next year and first month
{
nextmonth = 0;
nextyear = now.getFullYear() + 1;
}
else // otherwise go to next month of current year
{
nextmonth = now.getMonth() + 1;
nextyear = now.getFullYear();
}
var d = new Date( nextyear , nextmonth , 0); // setting day to 0 goes to last date of previous month
alert( d.getDay() ); // will alert the day of the week 0 being sunday .. you can calculate from there to get the first day of that week ..
Use getDay() to get the day of week of the last day in month and work from that (substracting the value from the number of days of the month should probably do the trick. +/- 1).
To determine whether it is a Monday, use .getDay() == 1. To determine if it is the last of the month, add seven days and compare months: nextMonday.setDate(monday.getDate()+7);
nextMonday.getMonth() == monday.getMonth();
The Javascript "Date" object is your friend.
function lastOfThisMonth(whichDay) {
var d= new Date(), month = d.getMonth();
d.setDate(1);
while (d.getDay() !== whichDay) d.setDate(d.getDate() + 1);
for (var n = 1; true; n++) {
var nd = new Date(d.getFullYear(), month, d.getDate() + n * 7);
if (nd.getMonth() !== month)
return new Date(d.getFullYear(), month, d.getDate() + (n - 1) * 7).getDate();
}
}
That'll give you the date (in the month, like 30) of the last day of the month that's the chosen day of the week (0 through 7).
Finding the last week of the month will depend on what you mean by that. If you mean the last complete week, then (if you mean Sunday - Saturday) find the last Saturday, and subtract 6. If you mean the last week that starts in the month, find the last Sunday.
You may also like to find the third Monday or the first Tuesday before or after a given date,
or flag every Wednesday between two dates.
Date.prototype.lastweek= function(wd, n){
n= n || 1;
return this.nextweek(wd, -n);
}
Date.prototype.nextweek= function(wd, n){
if(n== undefined) n= 1;
var incr= (n<0)? 1: -1,
D= new Date(this),
dd= D.getDay();
if(wd=== undefined) wd= dd;
if(dd!= wd) while(D.getDay()!= wd) D.setDate(D.getDate()+incr);
D.setDate(D.getDate()+7*n);
D.setHours(0, 0, 0, 0);
return D;
}
function lastMondayinmonth(month, year){
var day= new Date();
if(!month) month= day.getMonth()+1;
if(!year) year= day.getFullYear();
day.setFullYear(year, month, 0);
return day.lastweek(1);
}
alert(lastMondayinmonth())
i found such example that detects last monday of each week but it wont detect last monday of the month. maybe it will help to find better solution, that code looks short.
var dif, d = new Date(); // Today's date
dif = (d.getDay() + 6) % 7; // Number of days to subtract
d = new Date(d - dif * 24*60*60*1000); // Do the subtraction
alert(d); // Last monday.
OK, so far i came up with such solution making it a bit of my own way and getting a few things mentioned here. It works correct and always returns the last monday of current month.
//function that will help to check how many days in month
function daysInMonth(iMonth, iYear)
{
return 32 - new Date(iYear, iMonth, 32).getDate();
}
var dif = null;
d = new Date(); // Today's date
countDays = daysInMonth(d.getMonth(),d.getFullYear()); //Checking number of days in current month
d.setDate(countDays); //setting the date to last day of the month
dif = (d.getDay() + 6) % 7; // Number of days to subtract
d = new Date(d - dif * 24*60*60*1000); // Do the subtraction
alert(d.getDate()); //finally you get the last monday of the current month
Get the last day of the month:
/**
* Accepts either zero, one, or two parameters.
* If zero parameters: defaults to today's date
* If one parameter: Date object
* If two parameters: year, (zero-based) month
*/
function getLastDay() {
var year, month;
var lastDay = new Date();
if (arguments.length == 1) {
lastDay = arguments[0];
} else if (arguments.length > 0) {
lastDay.setYear(arguments[0]);
lastDay.setMonth(arguments[1]);
}
lastDay.setMonth(lastDay.getMonth() + 1);
lastDay.setDate(0);
return lastDay;
}
Get the last Monday:
/**
* Accepts same parameters as getLastDay()
*/
function getLastMonday() {
var lastMonday = getLastDay.apply(this, arguments);
lastMonday.setDate(lastMonday.getDate() - (lastMonday.getDay() == 0 ? 6 : (lastMonday.getDay() - 1)));
return lastMonday;
}
Get week of the year for a given day:
/**
* Accepts one parameter: Date object.
* Assumes start of week is Sunday.
*/
function getWeek(d) {
var jan1 = new Date(d.getFullYear(), 0, 1);
return Math.ceil((((d - jan1) / (24 * 60 * 60 * 1000)) + jan1.getDay() + 1) / 7);
}
Putting them together (assuming you're using Firebug):
// Get the last day of August 2006:
var august2006 = new Date(2006, 7);
var lastDayAugust2006 = getLastDay(august2006);
console.log("lastDayAugust2006: %s", lastDayAugust2006);
// ***** Testing getWeek() *****
console.group("***** Testing getWeek() *****");
// Get week of January 1, 2010 (Should be 1):
var january12010Week = getWeek(new Date(2010, 0, 1));
console.log("january12010Week: %s", january12010Week);
// Get week of January 2, 2010 (Should still be 1):
var january22010Week = getWeek(new Date(2010, 0, 2));
console.log("january22010Week: %s", january22010Week);
// Get week of January 3, 2010 (Should be 2):
var january32010Week = getWeek(new Date(2010, 0, 3));
console.log("january32010Week: %s", january32010Week);
console.groupEnd();
// *****************************
// Get the last week of this month:
var lastWeekThisMonth = getWeek(getLastDay());
console.log("lastWeekThisMonth: %s", lastWeekThisMonth);
// Get the last week of January 2007:
var lastWeekJan2007 = getWeek(getLastDay(2007, 0));
console.log("lastWeekJan2007: %s", lastWeekJan2007);
// Get the last Monday of this month:
var lastMondayThisMonth = getLastMonday();
console.log("lastMondayThisMonth: %s", lastMondayThisMonth);
// Get the week of the last Monday of this month:
var lastMondayThisMonthsWeek = getWeek(lastMondayThisMonth);
console.log("lastMondayThisMonthsWeek: %s", lastMondayThisMonthsWeek);