Javascript how to get full two year from current month? - javascript

I have question about getting full two years from the current date. So what i did id get the current month using the new date function and used the for loop to print each of the month. But, i cant really get it to work.... I will post the code that i did below. I would be really appreciate it if anyone can tell me the logic or better way of doing it.
For example: if today current date is august it store into an array from 8 / 2020 9/ 2020 ..... 12/ 2020, 1/2021 and goes to another year to 8/2022.
var d = new Date();
var year = d.getFullYear();
var dateStr;
var currentYear;
var storeMonthYear = [];
for(var i = 1; i <= 24; i++){
dateStr = d.getMonth() + i
currentYear = year;
if(dateStr > "12"){
dateStr = dateStr - 12
// currentYear = year;
// if(currentYear){
// }
storeMonthYear[i] = dateStr + "/" + (currentYear + 1);
}
else if(dateStr > "24"){
storeMonthYear[i] = dateStr + "/" + (currentYear + 1);
}
else{
storeMonthYear[i] = dateStr + "/" + currentYear;
}
storeMonthYear[i] = d.getMonth() + i
}
export const settlementPeriod = [
{
MonthYearFirstRow1: storeMonthYear[1],
MonthYearFirstRow2: storeMonthYear[2],
MonthYearFirstRow3: storeMonthYear[3],
MonthYearFirstRow4: storeMonthYear[4],
MonthYearFirstRow5: storeMonthYear[5],
MonthYearFirstRow6: storeMonthYear[6],
MonthYearFirstRow7: storeMonthYear[7],
MonthYearFirstRow8: storeMonthYear[8],
MonthYearFirstRow9: storeMonthYear[9],
MonthYearFirstRow10: storeMonthYear[10],
MonthYearFirstRow11: storeMonthYear[11],
MonthYearFirstRow12: storeMonthYear[12],
MonthYearSecondRow13: storeMonthYear[13],
MonthYearSecondRow14: storeMonthYear[14],
MonthYearSecondRow15: storeMonthYear[15],
MonthYearSecondRow16: storeMonthYear[16],
MonthYearSecondRow17: storeMonthYear[17],
MonthYearSecondRow18: storeMonthYear[18],
MonthYearSecondRow19: storeMonthYear[19],
MonthYearSecondRow20: storeMonthYear[20],
MonthYearSecondRow21: storeMonthYear[21],
MonthYearSecondRow22: storeMonthYear[22],
MonthYearSecondRow23: storeMonthYear[23],
MonthYearSecondRow24: storeMonthYear[24]
},
];

Create the date from today, get the month and year. Iterate from 0 to 24 for now till in 24 months. If month is 12 than set month to 0 and increment the year. Push the new datestring. Increment the month for the next step.
Note: Beacsue JS counts months form 0-11 you had to add for the datestring 1 for the month and make the change of year at 12 and not 13.
let date = new Date();
let year = date.getFullYear();
let month = date.getMonth();
let res=[];
for (let i=0; i<=24; i++) {
if (month===12) {
month = 0;
year++;
}
res.push(month+1 + '/' + year);
month++;
}
console.log(res);

Here you go, you get an array of strings like "8/2020","9/2020" etc from starting month to the last month including both( in total 25 months).
If you don't want to include last month just delete +1 from for loop condition.
let currentDate = new Date();
let settlementPeriod = [];
let numberOfMonths = 24;
for(let i=0;i<numberOfMonths+1;i++){
settlementPeriod.push(currentDate.getMonth()+1+"/"+currentDate.getFullYear()); //We add current date objects attributes to the array
currentDate = new Date(currentDate.setMonth(currentDate.getMonth()+1)); //Every time we add one month to it
}
console.log(settlementPeriod);

There are a couple of things that stick out in your code sample:
You're comparing strings and numbers (e.g. dateStr > "12"). This will lead to some weird bugs and is one of JS's most easily misused "features". Avoid it where possible.
You increment the year when you reach 12 months from now, rather than when you reach the next January
You're overwriting your strings with this line storeMonthYear[i] = d.getMonth() + i so your array is a bunch of numbers rather than date strings like you expect
Here's a code sample that I think does what you're expecting:
function next24Months() {
const today = new Date()
let year = today.getFullYear()
let monthIndex = today.getMonth()
let dates = []
while (dates.length < 24) {
dates.push(`${monthIndex + 1}/${year}`)
// increment the month, and if we're past December,
// we need to set the year forward and the month back
// to January
if (++monthIndex > 11) {
monthIndex = 0
year++
}
}
return dates
}
In general, when you're dealing with dates, you're probably better off using a library like Moment.js - dates/times are one of the most difficult programming concepts.

While #Ognjen 's answer is correct it's also a bit waseful if your date never escapes its function.
You don't need a new date every time:
function getPeriods(firstMonth, numPers){
var d = new Date(firstMonth.getTime()); // clone the start to leave firstMonth alone
d.setDate(1); // fix after #RobG
var pers = [];
var m;
for(var i = 0; i< numPers; i++){
m = d.getMonth();
pers.push(`${m+ 1}/${d.getFullYear()}`)
d.setMonth(m + 1); // JS dates automatically roll over. You can do this with d.setDate() as well and when you assign 28, 29, 31 or 32 the month and year roll over automatically
}
return pers;
}

Related

How to get the Week wise Start and End date in angularjs

Before I am using angularjs-DatePicker from this npm.
Here,I am able to select the date from the date picker.But now I have to fields as FromDate and ToDate which means the week StartDate and EndDate should show when any date pick in that week.
Ex: Like in Calender 01-08-2017 Start on Tue, So whenever Selects Any date from 01 to 05 then the two fields should show as FromDate as 01 and TODate as 06 and in the same whenever the user selects the 31-07-2017 the the Two fields should show as 30 and 31 of july.
I have an idea to achieve the ToDate from FromDate Calender control onchange event in DotNet as like below mentioned code
Convert.ToDouble(objstart.DayOfWeek)).ToString("dd-MM-yyyy")
But how to achieve this usecase in the angularjs.
Thanks
Ok, so what I'd do is to calculate different dates, and take the min/max depending on the start or end of the week.
Here:
//Use the date received, UTC to prevent timezone making dates shift
var pickedDate = new Date("08-03-2017UTC");
var startSunday = new Date(pickedDate);
startSunday.setDate(pickedDate.getDate() - pickedDate.getDay());
var startMonth = new Date(pickedDate);
startMonth.setDate(1);
var startDate = Math.max(startMonth,startSunday);
console.log("Start:" , new Date(startDate));
var endSaturday = new Date(pickedDate);
endSaturday.setDate(pickedDate.getDate() + (7-pickedDate.getDay()));
var endMonth = new Date(pickedDate);
endMonth.setMonth(pickedDate.getMonth()+1);//Add a month
endMonth.setDate(0);// to select last day of previous month.
var endDate = Math.min(endMonth,endSaturday);
console.log("End" , new Date(endDate));
The trick was to play with the dates, find all the possible start and end dates, then choose the right one with Math.min and Math.max which will compare the dates using their timestamp.
There is very good Library available in JavaScript to handle Date Manipulations.
https://github.com/datejs/Datejs
There is a method
Date.parse('next friday') // Returns the date of the next Friday.
Date.parse('last monday')
Using these method you can get the start and ending date of the week based on the current week.
I hope that it will help.
You can simply achieve this using the library moment. There are a lot of useful functions in this library.
var selectedDate = moment('Mon Aug 10 2017');
//If you want to get the ISO week format(Monday to Sunday)
var weekStart = selectedDate.clone().startOf('isoweek').format('MMM Do');
var weekEnd = selectedDate.clone().endOf('isoweek').format('MMM Do');
//If you want to get the Sunday to Saturday week format
var weekStart = selectedDate.clone().startOf('week').format('MMM Do');
var weekEnd = selectedDate.clone().endOf('week').format('MMM Do');
No need angular directive here, you could use the JavaScript extension which is below.
//get week from date
Date.prototype.getWeekNumber = function (weekstart) {
var target = new Date(this.valueOf());
// Set default for weekstart and clamp to useful range
if (weekstart === undefined) weekstart = 1;
weekstart %= 7;
// Replaced offset of (6) with (7 - weekstart)
var dayNr = (this.getDay() + 7 - weekstart) % 7;
target.setDate(target.getDate() - dayNr + 0);//0 means friday
var firstDay = target.valueOf();
target.setMonth(0, 1);
if (target.getDay() !== 4) {
target.setMonth(0, 1 + ((4 - target.getDay()) + 7) % 7);
}
return 1 + Math.ceil((firstDay - target) / 604800000);;
};
//get date rance of week
Date.prototype.getDateRangeOfWeek = function (weekNo, weekstart) {
var d1 = this;
var firstDayOfWeek = eval(d1.getDay() - weekstart);
d1.setDate(d1.getDate() - firstDayOfWeek);
var weekNoToday = d1.getWeekNumber(weekstart);
var weeksInTheFuture = eval(weekNo - weekNoToday);
var date1 = angular.copy(d1);
date1.setDate(date1.getDate() + eval(7 * weeksInTheFuture));
if (d1.getFullYear() === date1.getFullYear()) {
d1.setDate(d1.getDate() + eval(7 * weeksInTheFuture));
}
var rangeIsFrom = eval(d1.getMonth() + 1) + "/" + d1.getDate() + "/" + d1.getFullYear();
d1.setDate(d1.getDate() + 6);
var rangeIsTo = eval(d1.getMonth() + 1) + "/" + d1.getDate() + "/" + d1.getFullYear();
return { startDate: rangeIsFrom, endDate: rangeIsTo }
};
Your code can be look like this
var startdate = '01-08-2017'
var weekList = [];
var year = startdate.getFullYear();
var onejan = new Date(year, 0, 1);//first january is the first week of the year
var weekstart = onejan.getDay();
weekNumber = startdate.getWeekNumber(weekstart);
//generate week number
var wkNumber = weekNumber;
var weekDateRange = onejan.getDateRangeOfWeek(wkNumber, weekstart);
var wk = {
value: wkNumber
, text: 'Week' + wkNumber.toString()
, weekStartDate: new Date(weekDateRange.startDate)
, weekEndDate: new Date(weekDateRange.endDate)
};
weekList.push(wk);
I guess there is no directive or filter for this, you need to create one for yourself. you can refer date object from date-time-object

how to write day from numbers in javascript?

How would I write this expression in JavaScript?
It is to represent a date that is 2 weeks, counted by each passing Thursday, but excludes the thursday of the week the date was made.
NeededDay = Today + (18 - DayOfWeek(today))
or since it is Wednesday, it could be written?
var date = new Date();
var NeededDate = date.getDay() + (18-3);
or
I wrote this but I do not know if it is right?
var value = 3;
var GivenDate = value;
var GivenDay = value.getDay();
var daysToSecondThursday = Givenday2.setDate(GivenDay + Givenday2.setDate(18 - GivenDay));
alert("two weeks after next thursday is = " + daysToSecondThursday.val());
what is the correct way? ?
You could use:
function GetThursdayIn2Weeks(date)
{
var day = date.getDay();
// Add 2 weeks.
var newDate = new Date(date.setTime(date.getTime() + (14 * 86400000)));
// Adjust for Thursday.
var adjust = 4 - day;
if (adjust <= 0) // Might need to be changed - See comments!
adjust +=7;
// Apply Thursday adjustment.
newDate = new Date(newDate.setTime(newDate.getTime() + (adjust * 86400000)));
return newDate;
}
If the date passed in is Thursday, then it will return two weeks from the following Thursday. If this is not what you want, then adjust the if (adjust <= 0) code above to be:
if (adjust < 0)
Here is a jsFiddle: http://jsfiddle.net/kgjertsen/ec7vnezn/

Why its not giving me the correct total month?

Why it's not giving me the correct total month? (with compared to current mm-yyyy)
function get_total_month(mm,yyyy) {
// custom inputs
var start_date = new Date(yyyy, mm, 01);
// current date
var today_date = new Date();
var today_year = today_date.getFullYear();
var today_month = today_date.getMonth();
var today_day = today_date.getDate();
var end_date = new Date(new Date(today_year, today_month, today_day));
// compare the given date with current date to find the total months
var total_months = (end_date.getFullYear() - start_date.getFullYear())*12 + (end_date.getMonth() - start_date.getMonth());
return total_months;
}
alert(
get_total_month(01, 2014)
);
Giving me: 20 instead of 22
That's because the Date.prototype.getMonth method returns a 0-11 number. So:
January = 0
February = 1
...
December = 11
I think this is what you are looking for, it is another version of your code. But I think is shorter and easier to understand. What do you think?
(I added the +2 to adjust the result to what you are expecting the function to return)
function monthDifference(startDate) {
var months;
var currentDate = new Date();
months = (currentDate.getFullYear() - startDate.getFullYear()) * 12;
months -= startDate.getMonth() + 1;
months += currentDate.getMonth();
return months <= 0 ? 0 : (months + 2);
}
alert(monthDifference(new Date(2014,0)) );
alert(monthDifference(new Date(2013,11)) );

How to parse date string in jQuery and check if it is in the past

I need to check if the date is in the past. This is what I have so far. JSfiddle here.
var date = "09/12/2013";
var d = new Date();
var month = d.getMonth() + 1;
var day = d.getDate();
var todaysDate = +(('' + day).length < 2 ? '0' : '') + day + '/' + (('' + month).length < 2 ? '0' : '') + month + '/' + d.getFullYear();
if (date < todaysDate) {
alert("in the past");
} else {
alert("in the future");
}
Currently it is saying that the date was in the past, when it should be in the future. I know I need to parse the string as a date, but not sure how.
Help?
With that input format, you can't use a string comparison, because the least significant values are on the left. Note: I'm assuing that date is December 9th, 2013. If you're doing the American thing where it's September 12th, 2013, you'll have to adjust the indexes into parts below.
You could reverse the fields:
var date = "09/12/2013";
var parts = date.split('/');
date = parts[2] + "/" + parts[1] + "/" + parts[0];
...and then do your string comparison (being sure to construct the string for "today" in the same order — year/month/day).
If you're going to do that, you could go ahead and finish the job
var date = "09/12/2013";
var parts = date.split('/');
var date = new Date(parseInt(parts[2], 10), // year
parseInt(parts[1], 10) - 1, // month, starts with 0
parseInt(parts[0], 10)); // day
if (date < new Date()) {
// It's in the past, including one millisecond ago
}
...but of course, if you don't want the expression to be true for one millisecond ago, your string approach is fine.
var date = new Date("09/12/2013");
var d = new Date();
console.log(date>d); // true
var date = new Date("09/12/2011");
console.log(date>d); // false
JavaScript's native Date comparator only works on Date objects, whereas you are comparing Strings. You should parse date into a Date object, and then compare it with d.
//define parse(string) --> Date
if(parse(date) < new Date()) {
alert('past');
} else {
alert('future');
}

Compare day month and year

Good afternoon in my timezone.
I want to compare two dates , one of them is inserted by the user and the other is the present day. Snippet of code :
var dateString = "2012-01-03"
var date = new Date(dateString);
date < new Date() ? true : false;
This returns true, i think under the hood both Date objects are transformed to milliseconds and then compared , and if it is this way the "Today" object is bigger because of the hours and minutes.So what i want to do is compare dates just by the day month and year.What is the best approach ? Create a new Date object and then reset the hours minutes and milliseconds to zero before the comparison? Or extract the day the month and year from both dates object and make the comparison ? Is there any better approach ?
Thanks in advance
With the best regards.
Happy new year
Set the time portion of your created date to zeros.
var d = new Date();
d.setHours(0,0,0,0);
Since it's in yyyy-mm-dd format, you can just build the current yyyy-mm-dd from date object and do a regular string comparison:
var currentDate = new Date();
var year = currentDate.getFullYear();
var month = currentDate.getMonth()+1;
if (month < 10) month = "0" + month;
var day = currentDate.getDate();
if (day < 10) day = "0" + day;
currentDate = year + "-" + month + "-" + day;
var dateString = "2012-01-03"
var compareDates = dateString < currentDate ? true : false;
document.write(compareDates);
A production-ready example based on top of Accepted Answer
Add the following function to your Javascript
Date.prototype.removeTimeFromDate = function () {
var newDate = new Date(this);
newDate.setHours(0, 0, 0, 0);
return newDate;
}
Invoke it whenever you wish to compare
firstDate.removeTimeFromDate() < secondDate.removeTimeFromDate()

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