I have 2 dates which I need to compare to see if one is greater than the other but they are in different formats and I'm not sure of the best way to compare the 2.
The formats are:
1381308375118 (this is var futureDate)
which is created by
var today = new Date(); today.setHours(0, 0, 0, 0); var futureDate = new Date().setDate(today.getDate() + 56); //56 days in the future...
And the other format is
2013/08/26
Any ideas how I can compare the 2?
Without using a 3rd party library, you can create new Date objects using both those formats, retrieve the number of milliseconds (since midnight Jan 1, 1970) using getTime() and then simply use >:
new Date("2013/08/26").getTime() > new Date(1381308375118).getTime()
I strongly recommend using datejs library.
Thus this can be written in one single line:
Date.today().isAfter(Date.parse('2013/08/26'))
I would make sure that I am comparing the "date" element of each format and exclude any "time" element. Then with both dates converted to milliseconds, simply compare the values. You could do something like this. If dates are equal it returns 0, if the first date is less that the second then return -1, otherwise return 1.
Javascript
function compareDates(milliSeconds, dateString) {
var year,
month,
day,
tempDate1,
tempDate2,
parts;
tempDate1 = new Date(milliSeconds);
year = tempDate1.getFullYear();
month = tempDate1.getDate();
day = tempDate1.getDay();
tempDate1 = new Date(year, month, day).getTime();
parts = dateString.split("/");
tempDate2 = new Date(parts[0], parts[1] - 1, parts[2]).getTime();
if (tempDate1 === tempDate2) {
return 0;
}
if (tempDate1 < tempDate2) {
return -1;
}
return 1;
}
var format1 = 1381308375118,
format2 = "2013/08/26";
console.log(compareDates(format1, format2));
On jsfiddle
Maybe you can use Date.parse("2013/08/26") and compare with former one
Follow these steps to compare dates
Each of your date must to passed through Date object i.e. new Date(yourDate).
Now dates will have same format and these will be comparable
let date1 = new Date()
let date2 = "Jan 1, 2019"
console.log(`Date 1: ${date1}`)
console.log(`Date 2: ${date2}`)
let first_date = new Date(date1)
let second_date = new Date(date2)
// pass each of the date to 'new Date(yourDate)'
// and get the similar format dates
console.log(`first Date: ${first_date}`)
console.log(`second Date: ${second_date}`)
// now these dates are comparable
if(first_date > second_date) {
console.log(`${date2} has been passed`)
}
Related
const startDayOfTheWeek: number = moment().startOf('isoweek' as moment.unitOfTime.StartOf).valueOf();
if (this.card.dateScheduled.valueOf() < startDayOfTheWeek) {
this.card.dateScheduled = this.card.dateDue;
}
When using valueOf(), this.card.dateScheduled.valueOf() this gives me a value of the actual date. Not the millisecond relative to 1970 (a.k.a the Unix timestamp/epoch).
Why is that?
In moment.js there are many useful methods for comparing dates like isAfter, isBefore. So in your case use:
if (moment(this.card.dateScheduled).isBefore(startDayOfTheWeek))
I think you can take the benefits of inbuilt functionality.
Here is an example to compare dates in javascript.
const first = +new Date(); // current date
const last = +new Date(2014, 10, 10); // old date
console.log(first);
console.log(last);
// comparing the dates
console.log(first > last);
console.log(first < last);
I have date format returned as 05-Jan, 12-feb etc.. when i convert current date using date object in javascript . I did something like this
var curr = new Date(),
curr_year = curr.getFullYear(),
curr_month = curr.getMonth(),
curr_day = curr.getDay(),
today = new Date(curr_year, curr_month, curr_day, 0, 0, 0, 0);
console.log(today);
Here the today is returned as invalid date i needed the create a timestamp which should not include minutes secs and millisecs as zero for date comparison of month and date alone based on that i can categories .Is there way to dynamically create a date and compare those dates for given format.
And when i try to convert my date string using date object it returns year as 2001. how can i compare dates based upon current year.
For eg: in php i have used mktime to create a date dynamically from given date format and compare those results. Any suggestion would be helpful. Thanks.
You can leverage the native JS Date functionality to get human-readable date strings for time stamps.
var today = new Date();
console.log( today.toDateString() ); // Outputs "Mon Feb 04 2013"
Date comparison is also built in.
var yesterday = new Date();
yesterday.setDate( yesterday.getDate() - 1);
console.log( yesterday.toDateString() ); // Outputs "Sun Feb 03 2013"
console.log( yesterday < today ); //Outputs true
You can use the other built-in methods to fine-tune this comparison to be/not be sensitive to minutes/seconds, or to set all those to 0.
You said that you used mktime() in php, so what about this?
change to this :
var curr = new Date(),
curr_year = curr.getFullYear(),
curr_month = curr.getMonth()+1,
curr_day = curr.getDay(),
today = curr_month+'/'+curr_day+'/'+curr_year;
console.log(today);
(getMonth()+1 is because January is 0)
change the :
today = curr_month+'/'+curr_day+'/'+curr_year;
to whatever format you like.
I have found a way to convert the date into timestamp i have tried as #nbrooks implemented but .toDateString has built in date comparison which works for operator < and > but not for == operator to do that i have used Date.parse(); function to achieve it. Here it goes..
var curr = new Date(),
curr_year = curr.getFullYear(),
curr_month = curr.getMonth(),
curr_day = curr.getDate(),
today = new Date(curr_year, curr_month, curr_day, 0,0,0,0);
var dob = new Date('dob with month and date only'+curr_year);
if(Date.parse(dob) == Date.parse(today)){
//Birthdays....
}
This method can be used to create a timestamp for dynamically created date.Thanks for your suggestions.
I want to check to see if a date is before today. If it is then I want to display the date but not the time, if it is today then I want to display the time and not the date. The date I am checking is in the dd-mm-yyy hh:mm format and so they do not compare.
Please see what I have below so far:
var created = '25-05-2012 02:15';
var now = new Date();
if (created < now) {
created_format = [ format the date to be 25-05-2012 ]
} else {
created_format = [ format the date to be 02:15 ]
}
I have tried using now.dateFormat() and now.format() after seeing these in other examples but I get "is not a function" error messages.
Start by getting the parts of your date string:
var created = '25-05-2012 02:15';
var bits = created.split(/[-\s:]/);
var now = new Date();
// Test if it's today
if (bits[0] == now.getDate() &&
bits[1] == (now.getMonth() + 1) &&
bits[2] == now.getFullYear() ) {
// date is today, show time
} else {
// date isn't today, show date
}
Of course there are other ways, but I think the above is the easiest. e.g.
var otherDate = new Date(bits[2], bits[1] - 1, bits[0]);
now.setHours(0,0,0,0);
if (otherDate < now) {
// otherDate is before today
} else {
// otherDate is not before today
}
Similarly, once you've converted the string to a date you can use getFullYear, getMonth, getDate to compare with each other, but that's essentially the same as the first approach.
You can use getTime method and get timestamp. Then you can compare it with current date timestamp.
Can I convert iso date to milliseconds?
for example I want to convert this iso
2012-02-10T13:19:11+0000
to milliseconds.
Because I want to compare current date from the created date. And created date is an iso date.
Try this
var date = new Date("11/21/1987 16:00:00"); // some mock date
var milliseconds = date.getTime();
// This will return you the number of milliseconds
// elapsed from January 1, 1970
// if your date is less than that date, the value will be negative
console.log(milliseconds);
EDIT
You've provided an ISO date. It is also accepted by the constructor of the Date object
var myDate = new Date("2012-02-10T13:19:11+0000");
var result = myDate.getTime();
console.log(result);
Edit
The best I've found is to get rid of the offset manually.
var myDate = new Date("2012-02-10T13:19:11+0000");
var offset = myDate.getTimezoneOffset() * 60 * 1000;
var withOffset = myDate.getTime();
var withoutOffset = withOffset - offset;
console.log(withOffset);
console.log(withoutOffset);
Seems working. As far as problems with converting ISO string into the Date object you may refer to the links provided.
EDIT
Fixed the bug with incorrect conversion to milliseconds according to Prasad19sara's comment.
A shorthand of the previous solutions is
var myDate = +new Date("2012-02-10T13:19:11+0000");
It does an on the fly type conversion and directly outputs date in millisecond format.
Another way is also using parse method of Date util which only outputs EPOCH time in milliseconds.
var myDate = Date.parse("2012-02-10T13:19:11+0000");
Another option as of 2017 is to use Date.parse(). MDN's documentation points out, however, that it is unreliable prior to ES5.
var date = new Date(); // today's date and time in ISO format
var myDate = Date.parse(date);
See the fiddle for more details.
Yes, you can do this in a single line
let ms = Date.parse('2019-05-15 07:11:10.673Z');
console.log(ms);//1557904270673
Another possible solution is to compare current date with January 1, 1970, you can get January 1, 1970 by new Date(0);
var date = new Date();
var myDate= date - new Date(0);
Another solution could be to use Number object parser like this:
let result = Number(new Date("2012-02-10T13:19:11+0000"));
let resultWithGetTime = (new Date("2012-02-10T13:19:11+0000")).getTime();
console.log(result);
console.log(resultWithGetTime);
This converts to milliseconds just like getTime() on Date object
var date = new Date()
console.log(" Date in MS last three digit = "+ date.getMilliseconds())
console.log(" MS = "+ Date.now())
Using this we can get date in milliseconds
var date = new Date(date_string);
var milliseconds = date.getTime();
This worked for me!
if wants to convert UTC date to milliseconds
syntax : Date.UTC(year, month, ?day, ?hours, ?min, ?sec, ?milisec);
e.g :
date_in_mili = Date.UTC(2020, 07, 03, 03, 40, 40, 40);
console.log('miliseconds', date_in_mili);
In case if anyone wants to grab only the Time from a ISO Date, following will be helpful. I was searching for that and I couldn't find a question for it. So in case some one sees will be helpful.
let isoDate = '2020-09-28T15:27:15+05:30';
let result = isoDate.match(/\d\d:\d\d/);
console.log(result[0]);
The output will be the only the time from isoDate which is,
15:27
I have two dates 18-Aug-2010 and 19-Aug-2010 of this format. How to find whether which date is greater?
You will need to create a custom parsing function to handle the format you want, and get date objects to compare, for example:
function customParse(str) {
var months = ['Jan','Feb','Mar','Apr','May','Jun',
'Jul','Aug','Sep','Oct','Nov','Dec'],
n = months.length, re = /(\d{2})-([a-z]{3})-(\d{4})/i, matches;
while(n--) { months[months[n]]=n; } // map month names to their index :)
matches = str.match(re); // extract date parts from string
return new Date(matches[3], months[matches[2]], matches[1]);
}
customParse("18-Aug-2010");
// "Wed Aug 18 2010 00:00:00"
customParse("19-Aug-2010") > customParse("18-Aug-2010");
// true
You can do the parsing manually, for your given format, but I'd suggest you use the date.js library to parse the dates to Date objects and then compare.
Check it out, its awesome!
And moreover, its a great addition to your js utility toolbox.
The native Date can parse "MMM+ dd yyyy", which gives:
function parseDMY(s){
return new Date(s.replace(/^(\d+)\W+(\w+)\W+/, '$2 $1 '));
}
+parseDMY('19-August-2010') == +new Date(2010, 7, 19) // true
parseDMY('18-Aug-2010') < parseDMY('19-Aug-2010') // true
Firstly, the 'dd-MMM-yyyy' format isn't an accepted input format of the Date constructor (it returns an "invalid date" object) so we need to parse this ourselves. Let's write a function to return a Date object from a string in this format.
function parseMyDate(s) {
var m = ['jan','feb','mar','apr','may','jun','jul','aug','sep','oct','nov','dec'];
var match = s.match(/(\d+)-([^.]+)-(\d+)/);
var date = match[1];
var monthText = match[2];
var year = match[3];
var month = m.indexOf(monthText.toLowerCase());
return new Date(year, month, date);
}
Date objects implicitly typecast to a number (milliseconds since 1970; epoch time) so you can compare using normal comparison operators:
if (parseMyDate(date1) > parseMyDate(date2)) ...
Update: IE10, FX30 (and likely more) will understand "18 Aug 2010" without the dashes - Chrome handles either
so Date.parse("18-Aug-2010".replace("/-/g," ")) works in these browsers (and more)
Live Demo
Hence
function compareDates(str1,str2) {
var d1 = Date.parse(str1.replace("/-/g," ")),
d2 = Date.parse(str2.replace("/-/g," "));
return d1<d2;
}