I am trying to display data for a "Year to Date" range. I need it to show all the dates ranging from the first day of January 2021 until the current date (whatever day today is).
I previously had the data showing only the previous 30 days and had:
const today = new Date();
const startDate =
this.startDate || new Date(today.getFullYear(), today.getMonth(), today.getDate() - 30);
const endDate = this.endDate || today;
How can I get the data to show from January 1st, 2021 to whatever the current day is?
Here is how to create an array dateArray of all dates between the first of this year and today:
Date.prototype.addDays = function(days) {
var date = new Date(this.valueOf());
date.setDate(date.getDate() + days);
return date;
}
const today = new Date()
const startDate = new Date(today.getFullYear(), 0, 1);
var dateArray = new Array();
var currentDate = startDate;
while (currentDate <= today) {
dateArray.push(new Date(currentDate));
currentDate = currentDate.addDays(1);
}
console.log(dateArray)
This will work for every current year
const aDay = 24*60*60*1000;
const end = new Date()
// normalise - otherwise I would see last day of previous year until yesterday due to timezones
end.setHours(15,0,0,0);
const start = new Date(end.getFullYear(),0,0,15,0,0,0); // 31/12/previous year to get date 0
const days = (end.getTime()-start.getTime())/aDay
let t = start.getTime();
const dates = [...Array(days)] // create an array of days
.map(() => new Date(t+=aDay).toISOString().split('T')[0])
console.log(dates)
Using while
const aDay = 24*60*60*1000;
const end = new Date()
// normalise - otherwise I would see last day of previous year until yesterday due to timezones
end.setHours(15,0,0,0);
const start = new Date(end.getFullYear(),0,0,15,0,0,0); // 31/12/previous year to get date 0
const days = (end.getTime()-start.getTime())/aDay
let t = start.getTime();
const endTime = end.getTime();
const dates = [];
while (t<endTime) {
dates.push(new Date(t+=aDay).toISOString().split('T')[0])
}
console.log(dates)
As others have answered, just "better" — IMHO of course. :-)
// Default end is current date
function getDateRange(startDate, endDate = new Date()) {
// Default start to 1 Jan of endDate year
if (!startDate) {
startDate = new Date(endDate.getFullYear(), 0);
// Otherwise copy startDate so don't affect original
} else {
startDate = new Date(+startDate);
}
let result = [];
// Push timestamps into an array until endDate
while (startDate <= endDate) {
// Push date in YYYY-MM-DD format into result array
result.push(startDate.toLocaleDateString('en-CA'));
// Increment startDate
startDate.setDate(startDate.getDate() + 1);
}
return result;
}
// Dates from 1 Jan to today
console.log(getDateRange());
I have 2 dates and I need to create a 3rd date using those 2 dates.
if (document.getElementById("endDate"))
endDate = document.getElementById("endDate").value;
if (document.getElementById("presentDate"))
presentDate = document.getElementById("presentDate").value;
If Present date = "12/5/2018" and End date = "12/25/2018" then my New date = "12/26/2018";
Since, JavaScript date months range from 0-11 and also the dates are kind of messy, I am not getting the desired results.
What I tried:
var presentDt = new Date(presentDate);
var endDt = new Date(endDate);
var newDay = endDt.getUTCDate()+1;
var presentMonth = presentDt.getUTCMonth();
var presentYear = presentDt.getUTCFullYear();
var nextDate= presentMonth + '/' + endDay + '/' + presentYear;
Issue 1: This above code works but if my endDate is on the 31st, then adding UTCDate+1 makes it 32, which returns invalid date.
Issue 2: If I do UTCMonth(), it returns 11 but if I want to add 2 months then it returns 13 which is also invalid. The issue is basically that I am not able to manipulate the dates as I want.
I also tried moment, however I am having similar issues and I am not able to manipulate the dates easily as I want them to.
Also tried getDate and getMonth but it does the same thing.
Is there a better way of handling the overall date/time with JavaScript?
1: add/subtract days:
new Date(new Date().setDate(new Date().getDay() + 3))
2: add/subtract months:
new Date(new Date().setMonth(new Date().getMonth() + 3))
//your code
var presentDt = new Date(presentDate);
var endDt = new Date(endDate);
var newDay = new Date(new Date().setDate(endDt.getDay() + 2));
var presentMonth = presentDt.getUTCMonth();
var presentYear = presentDt.getUTCFullYear();
Since your input string is not in a format recognized by new Date() across environments, I suggest to use moment(String, String) to parse it.
Then you can use moment(Object), moment's setters (like year(), month() and date()) and format() to get the desired output.
Here a live sample:
var presentDt = "12/5/2018";
var endDt = "12/25/2018";
// Parse your input with momentjs
var mPresent = moment(presentDt, "MM/DD/YYYY");
var mEnd = moment(endDt, "MM/DD/YYYY");
// Create a new momnt object compliant with your needs
var nextDate = moment({
year: mPresent.year(), // get presentDt's year
month: mPresent.month(), // get presentDt's month
date: mEnd.add(1, 'day').date() // get endDt day of the month and add 1 day to it
});
// Display the result in the format you need
console.log(nextDate.format("MM/DD/YYYY"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>
Note that you will get 01 as day result when endDt represents the last day of the month.
This is what i did:
First i created the following functions to look at the number of days and months.
function formattedDate(date) {
var day = date.getDate();
var monthIndex = date.getMonth();
var year = date.getFullYear();
return (monthIndex + 1) + '/' + day + '/' + year;
}
function myNewDate(datestring) {
var dates = datestring.split("/");
var year, month, day;
if (dates.length < 3) {
dates = datestring.split("-");
year = dates[0];
month = dates[1] - 1;
day = dates[2];
} else {
year = dates[2];
month = dates[0] - 1;
day = dates[1];
}
var days = [31, 28, 31, 30, 31, 30 ,31, 31, 30, 31, 30, 31];
// Overflow day
if (day > days[month])
day = days[month];
return new Date(year, month, day);
}
function newDate(date1, date2) {
var days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
var year = date1.getFullYear();
var month = date1.getMonth() + 1;
var day = date2.getDate() + 1;
// Check leap year
if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
days[1] = 29;
// Overflow day
if (day > days[month])
day = days[month];
var newdate = new Date(year, month, day);
return newdate;
}
Here, i used the above function to create my new date. You can also add/subtract days/months as you want by updating the above.
var mpresent = myNewDate(presentDate);
var mstart = myNewDate(startDate);
var myDate = (formattedDate(newDate(mpresent, mstart)));
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 tried this but it fails
var diffDays1=(function(){
var oneDay = 24*60*60*1000; // hours*minutes*seconds*milliseconds
var secondDate = new Date(new Date().getFullYear()+1,4,5);
var firstDate = new Date();
return Math.round(Math.abs((firstDate.getTime() - secondDate.getTime())/(oneDay)));
})();
Wolfram alpha says it's 330 days, diffDays1 shows it's 359. This is probably due to daylight savings or something. Is there a way to accurately calculate days since without doing it server side.
The problem is that you're basing the month on April being 4, when April is 3 in Javascript. See https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date#Parameters
var diffDays1=(function(){
var oneDay = 24*60*60*1000; // hours*minutes*seconds*milliseconds
var secondDate = new Date(new Date().getFullYear()+1,3,5);
var firstDate = new Date();
return Math.round(Math.abs((firstDate.getTime() - secondDate.getTime())/(oneDay)));
})();
Why reinvent the wheel??
Use datejs
and after:
var startd = Date.parseExact(ind, "yyyy-MM-dd");
var endd = Date.parseExact(end, "yyyy-MM-dd");
var diff = new Date(endd - startd);
var days = diff/1000/60/60/24;
That's all folks!
The moment.js library (http://momentjs.com) handles this and a lot of other JavaScript date issues very easily and nicely. The diff function (http://momentjs.com/docs/#/displaying/difference/) will do exactly what you want.
The fromNow function is also super nice if want to display the number of days from now you could do something like:
moment([2014, 4, 5]).fromNow();
would produce something like "330 days" if it's 330 days away.
http://momentjs.com/docs/#/displaying/fromnow/
Here's a cleaner solution using moment, which handles all cases correctly (including today, upcoming birthday this year or not until next year, time zone, leap year, etc.):
const birthdate = '2018-12-15';
const today = moment().format('YYYY-MM-DD');
const years = moment().diff(birthdate, 'years');
const adjustToday = birthdate.substring(5) === today.substring(5) ? 0 : 1;
const nextBirthday = moment(birthdate).add(years + adjustToday, 'years');
const daysUntilBirthday = nextBirthday.diff(today, 'days');
Simple, fast, accurate!
Here's the same code, explained:
// This is the birthdate we're checking, in ISO 8601 format
const birthdate = '2018-12-15';
// Get today's date in ISO 8601 format
const today = moment().format('YYYY-MM-DD');
// Calculate current age of person in years (moment truncates by default)
const years = moment().diff(birthdate, 'years');
// Special case if birthday is today; we do NOT need an extra year added
const adjustToday = birthdate.substring(5) === today.substring(5) ? 0 : 1;
// Add age plus one year (unless birthday is today) to get next birthday
const nextBirthday = moment(birthdate).add(years + adjustToday, 'years');
// Final calculation in days
const daysUntilBirthday = nextBirthday.diff(today, 'days');
If the birthday is today, the result will be 0; if it is tomorrow, the result will be 1, and so on.
The selected solution doesn't work if the birthday is this year, because it sums 1 to getFullYear.
This is my solution, it also prevents two edge cases: birthday today and 1 day remaining.
const birthdayDay = 19;
const birthdayMonth = 11; // december === 11
const myBirthdayThisYear = new Date(new Date().getFullYear(), 11, 19).setHours(23, 59, 59);
export const daysUntilBirthday = () => {
const addToYear = myBirthdayThisYear > Date.now() ? 0 : 1;
const oneDay = 24 * 60 * 60 * 1000;
const secondDate = new Date(new Date().getFullYear() + addToYear, birthdayMonth, birthdayDay);
const firstDate = new Date();
const days = Math.round(Math.abs((firstDate.getTime() - secondDate.getTime()) / (oneDay)));
const daysOrDay = days === 1 ? 'day' : 'days';
return days !== 365 ? `${days} ${daysOrDay} until my birthday 😉😉` : '🎂 TODAY IS MY BIRTHDAY 🎂';
};
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);