I've tried to get the mother day date (first sunday of may) by Javascript. But the result of my code is 0.4.2021. Where is the fault or there a much more simplier way to get the mothers day date (dd.mm.yyyy) (german time zone).
var currentYear = new Date().getFullYear()
var mayFirst = new Date(currentYear + '-05-01');
var dayOfWeek = mayFirst.getUTCDay();
var firstSunday;
if (dayOfWeek === 0) {
firstSunday = mayFirst;
} else {
firstSunday = new Date();
firstSunday.setDate(1 + (7 - dayOfWeek));
}
var mothersDay = new Date(firstSunday);
mothersDay.setDate(firstSunday.getUTCDate() + 7);
mothersDay = new Date(mothersDay);
console.log(mothersDay.getDay() + "." + mothersDay.getMonth() + "." + mothersDay.getFullYear());
Here's the proper way of doing this, without error-prone calculations or string concatenation, including formatting it as DD.MM.YYYY:
// Mother's Day is the second sunday in May
const d = new Date();
d.setMonth(4); // May
d.setDate(8); // May 8 is the earliest possible date
// while not a sunday, move to next day
while (d.getUTCDay()) d.setDate(d.getDate() + 1);
const result = new Intl.DateTimeFormat('de-DE', { day: "2-digit", month: "2-digit", year: "numeric"}).format(d);
document.body.innerHTML += result;
getMonth() is 0 based so you need to add 1 to that. Also you want to use getDate() instead of getDay() to get the day value of the date.
I assume you want to get the 2nd sunday of may since the line below from your code adds 7 days. If you want the first sunday you should remove this line too.
mothersDay.setDate(firstSunday.getUTCDate() + 7);
var currentYear = new Date().getFullYear()
var mayFirst = new Date(currentYear + '-05-01');
var dayOfWeek = mayFirst.getUTCDay();
var firstSunday;
if (dayOfWeek === 0) {
firstSunday = mayFirst;
} else {
firstSunday = new Date();
firstSunday.setDate(1 + (7 - dayOfWeek));
}
var mothersDay = new Date(firstSunday);
mothersDay.setDate(firstSunday.getUTCDate() + 7);
mothersDay = new Date(mothersDay);
console.log(mothersDay.getDate() + "." + (mothersDay.getMonth() + 1) + "." + mothersDay.getFullYear());
In a form, I define a start date, an end date, and weekdays
Example:
Start date: 2017-02-07
End date: 2017-03-07
Weekdays: Monday and Thursday
Now I want to get all Mondays and Thursdays between start date and end date by using Javascript or jQuery.
Who can help me?
Thanks...
Simple code. Codepen
var startDate = new Date('2017-02-07');
var endDate = new Date('2017-02-17');
var monday = [];
var thursday = [];
for (var d = new Date(startDate); d <= new Date(endDate); d.setDate(d.getDate() + 1)) {
if(d.getDay()==1)
monday.push(d);
else if(d.getDay()==4)
thursday.push(d);
}
You can parse date and iterate over increment 1 day and getDay to map with sun(0) to sat(6)
var startDate = new Date("2017-02-07");
var endDate = new Date("2017-03-07");
var totalMon = [];
var totalThu = [];
for (var i = startDate; i <= endDate; ){
if (i.getDay() == 1){
totalMon.push(i.getFullYear() + "-" + (i.getMonth()+1) + "-" + i.getDate());
}
if (i.getDay() == 4){
totalThu.push(i.getFullYear() + "-" + (i.getMonth()+1) + "-" + i.getDate());
}
i.setTime(i.getTime() + 1000*60*60*24);
}
console.log(totalMon.length ,totalMon);
console.log(totalThu.length ,totalThu);
Below code finds number of Mondays. You can modify it to calculate any day. It basically finds the difference of days in two dates. Divide it by 7 (this is the number of times everyday will come). Now for pending days loop through the dates and check if a desired day comes in this loop.
var startDate = new Date(2017, 02, 07);
var endDate = new Date(2017, 03, 07);
var dayDiff = Math.round((endDate-startDate)/(1000*60*60*24));
var numberOfMondays = Math.floor(dayDiff/7);
var remainingDays = dayDiff%7;
for(i=0;i<remainingDays;i++)
{
var dateObj = new Date();
dateObj.setDate(endDate.getDate() - i);
if(dateObj.getDay() == 2)
numberOfMondays=numberOfMondays+1;
}
alert(numberOfMondays);
PS : the other two answer are looping through all the dates. I will not suggest this. In code above the number of iterations in loop will never exceed 6 irrespective of the difference in dates.
I am trying to display the date of the last Wednesday in the current month... so that it will automatically change to the correct date when the next month occurs. (So instead of having to say: "Performing the last wednesday of every month", I can dymanmically give the actual date.)
For example, I would want the date to show on the webpage as Wednesday, Sept 25th for this month, and then appear as Wednesday, Oct 30th next month.
A bonus additional solution would be if I could get the next month's date to display after the previous date has past. In my above example, when the current date is Sept 26-30 (any date after that last wednesday, but still in the same month).. the date would show the next performance date of Oct 30th.
It would be great if the solution was through html, javascript/jquery or asp.
Thanks,
SunnyOz
It depends on your criteria for "easy". Here's a simple function to do as required, it's 5 lines of working code that can be reduced to 4, but will lose a bit of clarity if that's done:
function lastDayInMonth(dayName, month, year) {
// Day index map - modify to suit whatever you want to pass to the function
var dayNums = {Sunday: 0, Monday:1, Tuesday:2, Wednesday:3,
Thursday:4, Friday:5, Saturday:6};
// Create a date object for last day of month
var d = new Date(year, month, 0);
// Get day index, make Sunday 7 (could be combined with following line)
var day = d.getDay() || 7;
// Adjust to required day
d.setDate(d.getDate() - (7 - dayNums[dayName] + day) % 7);
return d;
}
You can change the map to whatever, just determine what you want to pass to the function (day name, abbreviation, index, whatever) that can be mapped to an ECMAScript day number.
Edit
So in the case of always wanting to show the last Wednesday of the month or next month if it's passed:
function showLastWed() {
var now = new Date();
var lastWedOfThisMonth = lastDayInMonth('Wednesday', now.getMonth()+1, now.getFullYear());
if (now.getDate() > lastWedOfThisMonth().getDate()) {
return lastDayInMonth('Wednesday', now.getMonth()+2, now.getFullYear());
} else {
return lastWedOfThisMonth;
}
}
Note that the function expects the calendar month number (Jan = 1, Feb = 2, etc.) whereas the getMonth method returns the ECMAScript month index (Jan = 0, Feb = 1, etc.) hence the +1 and +2 to get the calendar month number.
You could use a javascript library such as moment.js:
http://momentjs.com/
and then get it with this:
moment().add('months', 1).date(1).subtract('days', 1).day(-4)
Here is an approach in JS:
var monthLengths = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];
function getLastWednesday() {
var d = new Date();
var month = d.getMonth();
var lastDay = monthLengths[month];
// mind leap years
if (month == 1) {
var year = d.getFullYear();
var isLeapYear = ((year % 4 == 0 && year % 100 > 0) || year % 400 == 0);
if (isLeapYear) lastDay++;
}
// get the weekday of last day in the curent mont
d.setDate(lastDay);
var weekday = d.getDay();
// calculate return value (wednesday is day 3)
if (weekday == 3) {
return lastDay;
}
else {
var offset = weekday - 3;
if (offset < 0) offset += 7;
return lastDay - offset;
}
}
I prefer to use an abstraction like moment.js as #Aralo suggested. To do it in raw JavaScript, however, you can use some code like this... create a function that gets all the days in a month. Then reverse-traverse the list to find the last day number. Wednesday is 3.
function getDaysInMonth(date) {
var dayCursor = new Date(today.getFullYear(), today.getMonth()); // first day of month
var daysInMonth = [];
while(dayCursor.getMonth() == date.getMonth()) {
daysInMonth.push(new Date(dayCursor));
dayCursor.setDate(dayCursor.getDate() + 1);
}
return daysInMonth;
}
function findLastDay(date, dayNumber) {
var daysInMonth = getDaysInMonth(date);
for(var i = daysInMonth.length - 1; i >= 0; i--) {
var day = daysInMonth[i];
if(day.getDay() === dayNumber) return day;
}
}
Then, to get the last Wednesday in the current month:
var today = new Date();
var lastWednesday = findLastDay(today, 3);
I Am trying to form a date which is 3 months before the current date. I get the current month by the below code
var currentDate = new Date();
var currentMonth = currentDate.getMonth()+1;
Can you guys provide me the logic to calculate and form a date (an object of the Date data type) considering that when the month is January (1), 3 months before date would be OCtober (10)?
var d = new Date();
d.setMonth(d.getMonth() - 3);
This works for January. Run this snippet:
var d = new Date("January 14, 2012");
console.log(d.toLocaleDateString());
d.setMonth(d.getMonth() - 3);
console.log(d.toLocaleDateString());
There are some caveats...
A month is a curious thing. How do you define 1 month? 30 days? Most people will say that one month ago means the same day of the month on the previous month citation needed. But more than half the time, that is 31 days ago, not 30. And if today is the 31st of the month (and it isn't August or Decemeber), that day of the month doesn't exist in the previous month.
Interestingly, Google agrees with JavaScript if you ask it what day is one month before another day:
It also says that one month is 30.4167 days long:
So, is one month before March 31st the same day as one month before March 28th, 3 days earlier? This all depends on what you mean by "one month before". Go have a conversation with your product owner.
If you want to do like momentjs does, and correct these last day of the month errors by moving to the last day of the month, you can do something like this:
const d = new Date("March 31, 2019");
console.log(d.toLocaleDateString());
const month = d.getMonth();
d.setMonth(d.getMonth() - 1);
while (d.getMonth() === month) {
d.setDate(d.getDate() - 1);
}
console.log(d.toLocaleDateString());
If your requirements are more complicated than that, use some math and write some code. You are a developer! You don't have to install a library! You don't have to copy and paste from stackoverflow! You can develop the code yourself to do precisely what you need!
I recommend using a library called Moment.js.
It is well tested, works cross browser and on server side(I am using it both in Angular and Node projects). It has great support for locale dates.
http://momentjs.com/
var threeMonthsAgo = moment().subtract(3, 'months');
console.log(threeMonthsAgo.format()); // 2015-10-13T09:37:35+02:00
.format() returns string representation of date formatted in ISO 8601 format. You can also use it with custom date format like this:.format('dddd, MMMM Do YYYY, h:mm:ss a')
A "one liner" (on many line for easy read)) to be put directly into a variable:
var oneMonthAgo = new Date(
new Date().getFullYear(),
new Date().getMonth() - 1,
new Date().getDate()
);
This should handle addition/subtraction, just put a negative value in to subtract and a positive value to add. This also solves the month crossover problem.
function monthAdd(date, month) {
var temp = date;
temp = new Date(date.getFullYear(), date.getMonth(), 1);
temp.setMonth(temp.getMonth() + (month + 1));
temp.setDate(temp.getDate() - 1);
if (date.getDate() < temp.getDate()) {
temp.setDate(date.getDate());
}
return temp;
}
To make things really simple you can use DateJS, a date library for JavaScript:
http://www.datejs.com/
Example code for you:
Date.today().add({ months: -1 });
If the setMonth method offered by gilly3 isn't what you're looking for, consider:
var someDate = new Date(); // add arguments as needed
someDate.setTime(someDate.getTime() - 3*28*24*60*60);
// assumes the definition of "one month" to be "four weeks".
Can be used for any amount of time, just set the right multiples.
I like the simplicity of gilly3's answer, but users will probably be surprised that a month before March 31 is March 3. I chose to implement a version that sticks to the end of the month, so a month before March 28, 29, 30, and 31 will all be Feb 28 when it's not a leap year.
function addMonths(date, months) {
var result = new Date(date),
expectedMonth = ((date.getMonth() + months) % 12 + 12) % 12;
result.setMonth(result.getMonth() + months);
if (result.getMonth() !== expectedMonth) {
result.setDate(0);
}
return result;
}
var dt2004_05_31 = new Date("2004-05-31 0:00"),
dt2001_05_31 = new Date("2001-05-31 0:00"),
dt2001_03_31 = new Date("2001-03-31 0:00"),
dt2001_02_28 = new Date("2001-02-28 0:00"),
result = addMonths(dt2001_05_31, -2);
console.assert(dt2001_03_31.getTime() == result.getTime(), result.toDateString());
result = addMonths(dt2001_05_31, -3);
console.assert(dt2001_02_28.getTime() == result.getTime(), result.toDateString());
result = addMonths(dt2001_05_31, 36);
console.assert(dt2004_05_31.getTime() == result.getTime(), result.toDateString());
result = addMonths(dt2004_05_31, -38);
console.assert(dt2001_03_31.getTime() == result.getTime(), result.toDateString());
console.log('Done.');
Do this
let currentdate = new Date();
let last3months = new Date(currentdate.setMonth(currentdate.getMonth()-3));
Javascript's setMonth method also takes care of the year. For instance, the above code will return 2020-01-29 if currentDate is set as new Date("2020-01-29")
For get date three monts prior to today :
let d = new Date(new Date().setMonth(new Date().getMonth() - 3))
console.log(d.toISOString().slice(0, 10))
// 2022-05-24 (today is 2022-08-24)
var d = new Date("2013/01/01");
console.log(d.toLocaleDateString());
d.setMonth(d.getMonth() + 18);
console.log(d.toLocaleDateString());
This is the Smallest and easiest code.
var minDate = new Date();
minDate.setMonth(minDate.getMonth() - 3);
Declare variable which has current date.
then just by using setMonth inbuilt function we can get 3 month back date.
There is an elegant answer already but I find that its hard to read so I made my own function. For my purposes I didn't need a negative result but it wouldn't be hard to modify.
var subtractMonths = function (date1,date2) {
if (date1-date2 <=0) {
return 0;
}
var monthCount = 0;
while (date1 > date2){
monthCount++;
date1.setMonth(date1.getMonth() -1);
}
return monthCount;
}
As I don't seem to see it already suggested....
const d = new Date();
const day = d.getDate();
const goBack = 3;
for (let i = 0; i < goBack; i++) d.setDate(0);
d.setDate(day);
This will give you the date of today's date 3 months ago as .setDate(0) sets the date to the last day of last month irrespective of how many days a month contains. day is used to restore today's date value.
var todayDate = new Date().toISOString().slice(0, 10);
var d = new Date(todayDate);
d.setMonth(d.getMonth() -3);
console.log(todayDate)
console.log(d.toISOString().slice(0, 10));
d.setMonth changed local time in browser try
const calcDate = (m) => {
let date = new Date();
let day = date.getDate();
let month = date.getMonth() + 1;
let year = date.getFullYear();
let days = 0;
if (m > 0) {
for (let i = 1; i < m; i++) {
month += 1;
if (month > 12) {
year += 1;
month = 1;
}
days += new Date(year, month, 0).getDate();
}
} else {
for (let i = m; i < 0; i++) {
month -= 1;
if (month < 1) {
year -= 1;
month = 12;
}
days -= new Date(year, month, 0).getDate();
}
}
const newTime = date.getTime() + 3600 * 24 * 1000 * days;
return new Date(newTime);
};
calcDate(3)//+3 month
Since "Feb 31th" is auto converted to "March 3" or "March 2", as a month before "March 31th", which is quite counterintuitive, I decided to do it just like how I do it in my mind.
Similar to #Don Kirkby 's answer, I also revise the date with the last day of the target month.
function nMonthsAgo(date, n) {
// get the target year, month, date
const y = date.getFullYear() - Math.trunc(n / 12)
const m = date.getMonth() - n % 12
let d = date.getDate()
if (d > 27) { // get a valid date
const lastDateofMonth = new Date(y, m + 1, 0).getDate()
d = Math.min(d, lastDateofMonth)
}
return new Date(y, m, d)
}
d = new Date('2022-03-31')
nMonthsAgo(d, 1).toLocaleDateString()
Finally, I love what #gilly3 said in his answer:
If your requirements are more complicated than that, use some math and write some code. You are a developer! You don't have to install a library! You don't have to copy and paste from stackoverflow! You can develop the code yourself to do precisely what you need!
for (let monthOfYear = 0; monthOfYear < 12; monthOfYear++) {
const maxDate = new Date();
const minDate = new Date();
const max = maxDate.setMonth(maxDate.getMonth() - (monthOfYear - 1), 0);
const min = maxDate.setMonth(minDate.getMonth() - (monthOfYear), 1);
console.log('max: ', new Date(max));
console.log('min: ', new Date(min));
}
In my case I needed to substract 1 month to current date. The important part was the month number, so it doesn't care in which day of the current month you are at, I needed last month. This is my code:
var dateObj = new Date('2017-03-30 00:00:00'); //Create new date object
console.log(dateObj); // Thu Mar 30 2017 00:00:00 GMT-0300 (ART)
dateObj.setDate(1); //Set first day of the month from current date
dateObj.setDate(-1); // Substract 1 day to the first day of the month
//Now, you are in the last month
console.log(dateObj); // Mon Feb 27 2017 00:00:00 GMT-0300 (ART)
Substract 1 month to actual date it's not accurate, that's why in first place I set first day of the month (first day of any month always is first day) and in second place I substract 1 day, which always send you to last month.
Hope to help you dude.
var dateObj = new Date('2017-03-30 00:00:00'); //Create new date object
console.log(dateObj); // Thu Mar 30 2017 00:00:00 GMT-0300 (ART)
dateObj.setDate(1); //Set first day of the month from current date
dateObj.setDate(-1); // Substract 1 day to the first day of the month
//Now, you are in the last month
console.log(dateObj); // Mon Feb 27 2017 00:00:00 GMT-0300 (ART)
var date=document.getElementById("date");
var d = new Date();
document.write(d + "<br/>");
d.setMonth(d.getMonth() - 6);
document.write(d);
if(d<date)
document.write("lesser then 6 months");
else
document.write("greater then 6 months");
Pass a JS Date object and an integer of how many months you want to add/subtract. monthsToAdd can be positive or negative. Returns a JS date object.
If your originalDateObject is March 31, and you pass -1 as monthsToAdd, then your output date will be February 28.
If you pass a large number of months, say 36, it will handle the year adjustment properly as well.
const addMonthsToDate = (originalDateObject, monthsToAdd) => {
const originalDay = originalDateObject.getUTCDate();
const originalMonth = originalDateObject.getUTCMonth();
const originalYear = originalDateObject.getUTCFullYear();
const monthDayCountMap = {
"0": 31,
"1": 28,
"2": 31,
"3": 30,
"4": 31,
"5": 30,
"6": 31,
"7": 31,
"8": 30,
"9": 31,
"10": 30,
"11": 31
};
let newMonth;
if (newMonth > -1) {
newMonth = (((originalMonth + monthsToAdd) % 12)).toString();
} else {
const delta = (monthsToAdd * -1) % 12;
newMonth = originalMonth - delta < 0 ? (12+originalMonth) - delta : originalMonth - delta;
}
let newDay;
if (originalDay > monthDayCountMap[newMonth]) {
newDay = monthDayCountMap[newMonth].toString();
} else {
newDay = originalDay.toString();
}
newMonth = (+newMonth + 1).toString();
if (newMonth.length === 1) {
newMonth = '0' + newMonth;
}
if (newDay.length === 1) {
newDay = '0' + newDay;
}
if (monthsToAdd <= 0) {
monthsToAdd -= 11;
}
let newYear = (~~((originalMonth + monthsToAdd) / 12)) + originalYear;
let newTime = originalDateObject.toISOString().slice(10, 24);
const newDateISOString = `${newYear}-${newMonth}-${newDay}${newTime}`;
return new Date(newDateISOString);
};
Following code give me Just Previous Month From Current Month even the date is 31/30 of current date and last month is 30/29/28 days:
<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the date after changing the month.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var d = new Date("March 29, 2017"); // Please Try the result also for "March 31, 2017" Or "March 30, 2017"
var OneMonthBefore =new Date(d);
OneMonthBefore.setMonth(d.getMonth(),0);
if(OneMonthBefore.getDate() < d.getDate() )
{
d.setMonth(d.getMonth(),0);
}else
{
d.setMonth(d.getMonth()-1);
}
document.getElementById("demo").innerHTML = d;
}
</script>
</body>
</html>
var d = new Date();
document.write(d + "<br/>");
d.setMonth(d.getMonth() - 6);
document.write(d);