Good day, I am generating 3 dates from a string, I hope the output was:
billing date: 2020/01/11
cutoff start: 2019/11/11
cuttof end: 2019/12/10
but I get the following:
billing date: 2020/11/10
cutoff start: 2019/11/10
cuttof end: 2019/12/10
I would like to know how javascript works with variables or what is the problem since everything is altered
var month = "Jan-20"
var coverage_month_obj = moment(month, 'MMM-YY').toDate();
var billing_date = new Date(coverage_month_obj.setDate(coverage_month_obj.getDate() + 10))
var cutoff_end = new Date(billing_date.setMonth(billing_date.getMonth() - 1))
cutoff_end = new Date(billing_date.setDate(billing_date.getDate() - 1))
var cutoff_start = new Date(billing_date.setMonth(billing_date.getMonth() - 1))
I would like to know how javascript works with variables or what is the problem since everything is altered
Put simply, calling setXXX on a javascript date variable updates that variable in place. ie, it is what we would call "mutable". You might have assumed dates were immutable and did not change in place.
To answer on a better way to achieve your goal, I'd suggest using the other functionality of momentjs to calculate your 3 dates from the given input string.
var month = "Jan-20"
var coverage_month = moment(month, 'MMM-YY');
//Jan-20 I need to convert it into date format and that the day is 11 (2020/01/11) cutoff start, are two months less from that date (2020/11/11) and cutoff end is one month less from Jan-20, but ends on day 10 (2020/12/10)
var billing_date = coverage_month.clone().add(10, 'days');
var cutoff_start = billing_date.clone().subtract(2, 'months');
var cutoff_end = billing_date.clone().subtract(1,'months').subtract(1,'day')
console.log("billing_date",billing_date);
console.log('cutoff_start',cutoff_start);
console.log('cutoff_end',cutoff_end);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>
Related
I am trying to set up a Google App Script function that grabs a date (formatted dd/mm/yy) from the last column of a spread, and creates a new column with the date + one day.
I have seen previous solutions and tried to use the same, i.e.newDate.setDate(lastDate.getDate()+1) but have had issues getting the value formatted correctly in the script. This is a variation of my code that I'm using to loop through for a year's worth of values to see what I get:
for (var i=0;i<365;i++){
var lastRow = outputSheet.getLastRow();
var newDate = new Date();
var lastDate = outputSheet.getRange(lastRow,1).getValue();
var newDateRng = outputSheet.getRange(lastRow+1,1);
Logger.log(lastDate + 1, typeof lastDate, typeof (lastDate + 1));
newDate.setDate(lastDate.getDate());
Logger.log(newDate);
newDate.setDate((newDate.getDate() + 1));
Logger.log(newDate);
var newDateFormatted = Utilities.formatDate(newDate, ss.getSpreadsheetTimeZone(), "dd/MM/YY");
Logger.log(newDateFormatted);
newDateRng.setValue(newDateFormatted);
}
With a start date of "01/03/2020", I get the following behaviour:
01/03/2020
02/05/2020
03/05/2020
...
31/05/2020
01/06/2020
02/05/2020
03/05/2020
...
31/05/2020
01/06/2020
02/05/2020
...
etc. All the way through the year. Although the day increase, the month seems to reset after the first day of the month.
As a note, I am specifically looking to pick the date off of the spreadsheet rather than using new Date as today and new Date +1 as tomorrow.
Thanks
You need to use a different variable in the loop otherwise you will always return to the same month.
Also avoid using strings for the result, keep date objects and display it properly.
The code goes like this :
function otherTest(){
var lastDate = SpreadsheetApp.getActiveSheet().getActiveCell().getValue();
var date = new Date(lastDate); // create new date object
var result = [];
for (var i=0;i<365;i++){
date=new Date(date).setDate(new Date(date).getDate()+1)
Logger.log('date='+new Date(date))
result.push([new Date(date)]);
}
SpreadsheetApp.getActiveSheet().getRange(1,2,result.length,1).setValues(result).setNumberFormat('dd/MM/yyyy');
}
So, I need to calculate age by subtracting "todays" date from the converted date of an input field, entered by the user. Although it needs cleaned up, the below code works, I had to get creative as RN uses a different JS execution environment... see here.
My question, without adding the "+1" to this snippet "b.getMonth() + 1", the math on the date subtraction comes back 1 month off every time. When I add the "+1" it works like a charm, why? If it's a logical fix, I don't mind keeping the "+1," but I would surely like to know why the "+1" is necessary.
Also, totally open to improved solutions to this problem, keep in mind I had a much simpler function that worked great while debugger was open, once closed, it did not work, see the link above.
getVerifyBirthday(birthday) {
const b = new Date();
var verify = birthday.length;
const utc2 = Date.UTC(b.getFullYear(), b.getMonth() + 1, b.getDate());
if (verify === 10) {
const splitBirth = birthday.split('-');
var mydate = new Date(splitBirth[2], splitBirth[0], splitBirth[1]);
const a = mydate;
const utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate());
const diffTime = Math.abs(utc2 - utc1);
const diffYears = (diffTime / (3.15576e+10));
this.setState({ diffYears: diffYears});
return diffYears >= 13;
} else {}
}
Update
I ended up refactoring my original function, leaving the (+1) on months due to months starting at 0, as mentioned below. I still had to split both dates, when I didn't split both, my age came back NaN/Undefined; not sure if this goes back to the RN execution environment vs browser, but I digress.
I'd make a few of my own suggestions over here:
there's no need to hussle with UTC dates (to make sure whether the user in his timezone has already reached the age of 13, assuming along the way that he or she was born in that same timezone ;)
there's no need to split mm-dd-yyyy date string to convert into Date, it may be parsed by new Date()
counting years as 365.25 days has certain error margin depending on the exact leap years quantity that passed since the user's birth year, instead whole years may be compared together with dates
To me, it makes more sense to decompose date strings into days, months and years and make decision based on full years difference minus 1 year (if the person didn't yet celebrate his/her birthday this year):
const today = new Date().toISOString().slice(0,10), // yyyy-mm-dd
birthday = '1982-06-21',
[bYear, bMonth, bDay] = birthday.split('-'),
[tYear, tMonth, tDay] = today.split('-'),
diffYears = tYear - bYear - (bMonth > tMonth || bDay > tDay ? 1 : 0)
console.log(diffYears)
.as-console-wrapper{min-height:100%;}
Months are zero-based in JavaScript Date objects. However, if you get a formatted string, they start from 1:
const date = new Date(2020, 1, 17); // 17th of February 2020
console.log("getMonth:", date.getMonth()); //month is 1
console.log("formatted:", date.toISOString()); //month is 2
So, actually what happens is that you're shifting both dates a month forward. This sort of works:
const originDate = new Date(2020, 1, 17); // 17th of February 2020
const originString = "2020-02-17".split("-");
const dateFromDate = new Date(originDate.getFullYear(), originDate.getMonth() + 1, originDate.getDate())
const dateFromString = new Date(originString[0], originString[1], originString[2])
console.log("dateFromDate:", dateFromDate); //month is 3
console.log("dateFromString:", dateFromString); //month is 3
When you do the subtraction it evens out but you can still run into an overflow of the date for months with different number of days:
const originDate = new Date(2020, 0, 31); // 31st of January 2020
const dateFromDate = new Date(originDate.getFullYear(), originDate.getMonth() + 1, originDate.getDate())
console.log("dateFromDate:", dateFromDate); // 1st of March 2020
This still works logically for most cases, however you are bound to run into a problem at some point if you shift months forward. So, instead you should be doing the opposite and subtracting 1 when converting a 1-based number into a Date object:
const originString = "2020-02-17".split("-");
const dateFromString = new Date(originString[0], originString[1] - 1, originString[2])
console.log("dateFromString:", dateFromString); //month is 2
I am trying to calculate the days between 2 dates and it is working as far as I can tell but I keep getting stupidly high numbers which clearly isn't right, I have a feeling this is the way my dates are set out. my dates are set out as dd/mm/yyyy and this is the code I am using:
var diff = new Date(end_date - start_date);
var days = diff/1000/60/60/24;
console.log("diff=>"+days);
This is the question I used to get the answer:
JavaScript date difference Days
When it writes to the console this is the result I get:
diff=>17301.95833332176
I have had a play with the code, although I have not used HTML, i set the vars statically below.
var end_date = new Date("May 25, 2017");
var start_date = new Date("May 23, 2017");
var diff = new Date(end_date - start_date);
var days = diff/1000/60/60/24;
console.log("diff=>"+days);
I have also checked it with a 3 value date format
var end_date = new Date(2017,4,25);
var start_date = new Date(2017,4,23);
var diff = new Date(end_date - start_date);
var days = diff/1000/60/60/24;
console.log("diff=>"+days);
I manage to get an output of 2. Which is what i expected. The code you supplied looks ok to me. Maybe look at the HTML to check that the values being passed are in the correct format.
Jquery datepicker may be of help to you here.
You could also use moment: https://momentjs.com
var moment = require('moment');
var start_moment = moment(start_date);
var end_moment = moment(end_date);
var days = start_moment.diff(end_moment, 'days');
console.log("diff=>" + days);
You can also get weeks, months etc. with this method
Easy solution, is to use countBtw
var { date } = require('aleppo')
//..
date.countBtw('all', date1, date2)
I have function:
sample(date){
//operations, for example add one week (7 days)
return date;
}
var one = new Date('2012-07-16');
var two = new Date('07/16/2012');
var new = sample(one); // or sample(two)
var day = new.getDate();
var month = new.getMonth();
var year = new.gerYear();
alert(day + month + year);
and now i would like show this date, but how can i check format this date?
For example:
alert(sample(one));
should show me date with format 2012-07-23
and if
alert(sample(one));
should show me 07/23/2012
but how can i check format current date? is this possible?
Date objects don't "remember" the format with which they were created - they're just a wrapper for the standard Javascript "milliseconds since the epoch" time values.
You'll need to either roll your own "date to string" functions, or use one of the popular existing libraries (e.g. Datejs)
I need to know the date for last Sunday for given date in php & javascript
Let's have a function give_me_last_Sunday
give_me_last_Sunday('20110517') is 20110515
give_me_last_Sunday('20110604') is 20110529
The full backup is done on Sundays = weekly. If I want to restore daily backup I need full (weekly) and daily backup. I need to copy backup files before restoring to temp directory so I restoring daily backup I need to know what weekly backup file I need to copy along the daily file.
My thought was to get Julian representation (or something similar) for the given date and then subtract 1 and check if it is Sunday ... Not sure if this is the best idea and how to convert given date into something I can subtract.
Based on Thomas' effort, and provided the input string is exactly the format you specified, then:
function lastSunday(d) {
var d = d.replace(/(^\d{4})(\d{2})(\d{2}$)/,'$1/$2/$3');
d = new Date(d);
d.setDate(d.getDate() - d.getDay());
return d;
}
Edit
If I were to write that now, I'd not depend on the Date object parsing the string but do it myself:
function lastSunday(s) {
var d = new Date(s.substring(0,4), s.substring(4,6) - 1, s.substring(6));
d.setDate(d.getDate() - d.getDay());
return d;
}
While the format yyyy/mm/dd is parsed correctly by all browsers I've tested, I think it's more robust to stick to basic methods. Particularly when they are likely more efficient.
Ok so this is for JavaScript only. You have an input that you need to extract the month, date, and year from. The following is just partly an answer then on how to get the date:
<script type="text/javascript">
var myDate=new Date();
myDate.setFullYear(2011,4,16)
var a = myDate.getDate();
var t = myDate.getDay();
var r = a - t;
document.write("The date last Sunday was " + r);
</script>
So the setFullYear function sets the myDate to the date specified where the first four digits is the year, the next are is the month (0= Jan, 1= Feb.,...). The last one is the actually date. Then the above code gives you the date of the Sunday before that. I am guessing that you can add more code to get the month (use getMonth() method). Here are a few links that might be helpful
http://www.w3schools.com/js/js_obj_date.asp
http://www.w3schools.com/jsref/jsref_setFullYear.asp
http://www.w3schools.com/jsref/jsref_getMonth.asp
(You can probably find the other functions that you need)
I hope this helps a bit even though it is not a complete answer.
Yup and strtotime has been ported to JS for eg http://phpjs.org/functions/strtotime:554 here.
final code (big thanks to #Thomas & #Rob)
function lastSunday(d) {
var d = d.replace(/(^\d{4})(\d{2})(\d{2}$)/,'$1/$2/$3');
d = new Date(d);
d.setDate(d.getDate() - d.getDay());
year = d.getFullYear()+'';
month = d.getMonth()+1+'';
day = d.getDate()+'';
if ( month.length == 1 ) month = "0" + month; // Add leading zeros to month and date if required
if ( day.length == 1 ) day = "0" + day;
return year+month+day;
}