I have a date field which accepts if the month is unknown. And I calculate the age from the date entered and the current date and time.
var birthDate = new Date("12 UNK 1995");
var now = new Date();
var age = now.getFullYear() - birthDate.getFullYear();
document.write("Your Age is: " + age);
If the run this is throwing me NaN error. I think it is because of that invalid date format.
Is there any way that I can calculate the age even if the month is unknown based on the year only in any kind of date formate?
If the month is unknown then the normal way programmatically to set it to the middle of the year – to July. I know this problem in India – some people do not know their birth date sometimes.
For example like follows:
var month = "UNK"; // TODO: here is your code to get the month name from field
month = month == "UNK" ? "JUL" : month;
var birthDate = new Date("12 " + month + " 1995");
var now = new Date();
var age = now.getFullYear() - birthDate.getFullYear();
document.write("Your Age is: " + age);
But note that your calculation is not really correct because you do not calculate with full date (day, month, year, hour, minutes).
My suggestion
But I would like to suggest to use a new HTML5 input field type date (see this link) which looks like follows (go with mouse pointer over this field):
<input name="birthdate" type="date" required>
And all users have to put in this date on their's own accountability. In this case they have to choose one date and you will do not have the accountability for this.
You have the year already in a string so extract it from the string and then substract from year now.
Related
I only want the date range to be selectable for future days and the first day should be before or the same day as the 2nd day to create a date range.
Input is
first date: 01/23/2020
second date: 03/19/2020
currdate: 12/11/2019
var curdate = month + "/" + day + "/" + year;
if(smsBlackoutFirstDateSelect.value > smsBlackoutSecondDateSelect.value){
alert("second date is before first date");
} else if(smsBlackoutFirstDateSelect.value <= curdate){
alert("first date is on or before today" + " " + smsBlackoutFirstDateSelect.value + " " +
smsBlackoutSecondDateSelect.value + " " + curdate);
} else {
some success function;
}
Output is :
first date is on or before today 01/23/2020 03/19/2020 12/11/2019
any idea why it isn't comparing years?
if you are referring to the comparison of curdate with smsBlackoutFirstDateSelect.value,
curdate is not a date field.
if you want date comparison to convert it to date by
var d1 = new Date(curdate);
and use it
you can refer below question
Compare two dates with JavaScript
I see that you're using a string to represent the date. This won't work well. Ideally, we should use javascript Date variables to handle the sorting as needed.
Try something like this and see how it compares.
Example:
3 numbers specify year, month, and day:
var curdate = new Date(2018, 11, 24);
I can't see how smsBlackoutFirstDateSelect is defined. It may also need to be casted to Dates() separately. See the other methods to create a Date() referenced below.
Reference: https://www.w3schools.com/js/js_dates.asp
I am trying to prepopulate a date into an html "date" input field, but it ignores the values I try to pass:
<html>
...
<input id='date' type='date'>
...
</html>
<script>
...
var myDate = new Date();
$("#date").val(myDate);
...
I have also tried passing the date object as a string
var myDate = new Date().toDateString();
$("#date").val(myDate);
When I open the form, the date field is blank. If I eliminate the type="date" tag, the value shows up as a string, but then I don't have access to the datepicker. How do I pre-populate a date input and still have use of the datepicker? I'm stumped.
Thanks.
It must be set in ISO-format.
(function () {
var date = new Date().toISOString().substring(0, 10),
field = document.querySelector('#date');
field.value = date;
console.log(field.value);
})()
http://jsfiddle.net/GZ46K/
Why Not to Use toISOString()
The <input type='date'> field takes a value in ISO8601 format (reference), but you should not use the Date.prototype.toISOString() function for its value because, before outputting an ISO8601 string, it converts/represents the date/time to UTC standard time (read: changes the time zone) (reference). Unless you happen to be working in or want that time standard, you will introduce a bug where your date will sometimes, but not always, change.
Populate HTML5 Date Input from Date Object w/o Time Zone Change
The only reliable way to get a proper input value for <input type='date'> without messing with the time zone that I've seen is to manually use the date component getters. We pad each component according to the HTML date format specification (reference):
let d = new Date();
let datestring = d.getFullYear().toString().padStart(4, '0') + '-' + (d.getMonth()+1).toString().padStart(2, '0') + '-' + d.getDate().toString().padStart(2, '0');
document.getElementById('date').value = datestring;
/* Or if you want to use jQuery...
$('#date').val(datestring);
*/
<input id='date' type='date'>
Populate HTML5 Date & Time Fields from Date Object w/o Time Zone Change
This is beyond the scope of the original question, but for anyone wanting to populate both date & time HTML5 input fields from a Date object, here is what I came up with:
// Returns a 2-member array with date & time strings that can be provided to an
// HTML5 input form field of type date & time respectively. Format will be
// ['2020-12-15', '01:27:36'].
function getHTML5DateTimeStringsFromDate(d) {
// Date string
let ds = d.getFullYear().toString().padStart(4, '0') + '-' + (d.getMonth()+1).toString().padStart(2, '0') + '-' + d.getDate().toString().padStart(2, '0');
// Time string
let ts = d.getHours().toString().padStart(2, '0') + ':' + d.getMinutes().toString().padStart(2, '0') + ':' + d.getSeconds().toString().padStart(2, '0');
// Return them in array
return [ds, ts];
}
// Date object
let d = new Date();
// Get HTML5-ready value strings
let dstrings = getHTML5DateTimeStringsFromDate(d);
// Populate date & time field values
document.getElementById('date').value = dstrings[0]
document.getElementById('time').value = dstrings[1]
/* Or if you want to use jQuery...
$('#date').val(dstrings[0]);
$('#time').val(dstrings[1]);
*/
<input type='date' id='date'>
<input type='time' id='time' step="1">
Thank you j08691. That link was the answer.
To others struggling like me, when they say input is "yyyy-mm-dd" the MEAN it!
You MUST have 4 digits for the year.
You MUST have a dash and no spaces.
You MUST have 2 digits for day and month.
In my example myDate.getMonth for January would only return "1" (actually it returns "0" because for some reason javascript counts months from 0-11). To get this right I had to do the following:
var myDate, day, month, year, date;
myDate = new Date();
day = myDate.getDate();
if (day <10)
day = "0" + day;
month = myDate.getMonth() + 1;
if (month < 10)
month = "0" + month;
year = myDate.getYear();
date = year + "-" + month + "-" + day;
$("#date").val(date);
I hope this helps others not waste hours like I did testing this before October or before the 10th of the month! LOL
Here is an answer based on Robin Drexlers but in local time.
//Get the local date in ISO format
var date = new Date();
date.setMinutes(date.getMinutes() - date.getTimezoneOffset());
var datestr = date.toISOString().substring(0, 10);
//Set the field value
var field = document.querySelector('#date');
field.value = datestr;
If it's a datetime field you're modifying (as opposed to just the date) don't forget to add the time T00:00, or change the substring to 16 characters for example:
//Get the local date and time in ISO format
var date = new Date();
date.setMinutes(date.getMinutes() - date.getTimezoneOffset());
var datestr = date.toISOString().substring(0, 16);
//Set the field value
var field = document.querySelector('#datetime');
field.value = datestr;
This below code populates the local date . The accepted answer populates UTC date.
var date = new Date();
field = document.querySelector('#date-id');
var day = date.getDate();
if(day<10){ day="0"+day;}
var month = date.getMonth()+1;
if(month<10){ month="0"+month;}
field.value = date.getFullYear()+"-"+month+"-"+day;
I don't have the reputation points to comment on another answer, so I'll just add a new answer. And since I'm adding an answer, I'll give more details than I would've in a comment.
There's an easier way to zero pad than all of the juggling that everyone is doing here.
var date = new Date();
var month = ('0' + (date.getMonth() + 1)).slice(-2);
var day = ('0' + date.getDate()).slice(-2);
var year = date.getFullYear();
var htmlDate = year + '-' + month + '-' + day;
console.log("Date: " + htmlDate);
Today, the output would be
Date: 2020-01-07
The code is building a dynamic string by prepending a quoted zero, then taking the last 2 characters with slice(-2). This way, if the zero makes it 01, the last 2 are 01. If the zero makes it 011, then the last two are 11.
As for the month starting at zero silliness, you can also add 1 dynamically before prepending the zero and everything still works. You just have to do the math operation before turning it into a string.
As a side note, I've noticed that when you update a date field, you have to hide the field before setting the value and show it after setting. I don't do this often enough, so I have to re-struggle each time I need to deal with it. Hopefully this will help someone from the future.
waves to future people
Lets say there are two textboxes, one to enter in a date and the other to enter in time. Below is an example:
<p><strong>Date:</strong> <input type="text" id="datetxt"></p>
Example of how date is displayed: 25-05-1995
<p><strong>Time:</strong> <input type="text" id="timetxt"></p>
Example of how time is displayed: 14:25
Can someone suggest a way in javascript to compare values of the date and time from the textboxes to the current date and time so if the current date and time is past the date and time entered in the textboxes, then it should display and alert?
Try this
var dateParts = document.getElementById("datetxt").value.split("-");
var timeParts = document.getElementById("timetxt").value.split(":");
var valueDate = new Date(dateParts[2], (dateParts[1] - 1) ,dateParts[0], timeParts[0], timeParts[1]);
if( (new Date).getTime() > valueDate .getTime() )
{
alert("passed");
}
Live example: http://jsfiddle.net/TJEMr/
You need to massage your date string into a compatible date format:
//datetxt textbox value, split on dashes
var date = "25-05-1995".split("-"),
//timetxt textbox value
time = "14:25",
//put it into format: YYYY-MM-DDThh:mm and creates a date object from it
dateObj = new Date(date[2] + '-' + date[1] + '-' + date[0] + 'T' + time);
//if today is greater than we have passed that DateTime
if(new Date() > dateObj) {
alert("After entered date");
} else {
alert("Not passed yet!");
}
Working example: jsFiddle
I would like to have an input field with a button next to it.
On the input field I will enter a date like this:
2011-07-08
And when I hit the button it should read the time that has been entered on the input field and subtract it with 3 months and one day.
Is this possible?
Thanks in advance
Yes. First you read the date and you convert to a date object
var dateString = document.getElementById('id of your field').value,
date = new Date(dateString);
then you subtract 91 days and output the result
date.setDate(date.getDate() - 91);
alert(date.toString());
Here I assume for simplicity that you actually want 91 days and not 3 months and one day. If you want three months and one day you will do
date.setMonth(date.getMonth() - 3);
date.setDate(date.getDate() - 1);
alert(date.toString());
The Date object will take care of overflows, leap years and everything.
If you want to write it to same field, taking care of zeroes, you can do
function assureTwoDigits(number) {
if (number > 9) {
return '-' + number;
}
else {
return '-0' + number;
}
}
and change the last line to
document.getElementById('id of your field').value = date.getFullYear() + assureToDigits(date.getMonth()) + assureTwoDigits(date.getDate());
You can use Date objects (see here):
extract year, moth and day from the string (using a regular expression or splitting by '-')
buid a new Date object with that data
subtract the date interval
build the string back
The simplest way would be to split it into an array, then use a couple of if/else statements:
var date = (whatever you're pulling the date in as).split('-');
if (date[1] > 3)
date[1] = date[1] - 3;
else
date[0] = date[0] - 1;
var dateOverflow = date[1]-3;
date[1] = 12 - dateOverflow;
And then the same for the days.
Yes, it's possible and it's the most clean if you can do it without some arcane regex magic. Start by converting the date to a Date object:
// this will get you a date object from the string:
var myDate = new Date("2011-07-08");
// subtract 3 months and 1 day
myDate.setMonth(myDate.getMonth()-3);
myDate.setDay(myDate.getMonth(), myDate.getDay()-1);
// And now you have the day and it will be correct according to the number of days in a month etc
alert(myDate);
I have created a form in Adobe Pro and i have added some JavaScript to it. But i have two problems.
1) Is there a "Document Finished Loading"-action? I have a date field on the form and i would like that it automatically adds todays date into that field when the user opens the document to fill in the form fields.
2) The date method that i am using doesn't work properly, i have this code:
var dt = new Date();
var day = dt.getDate();
var month = dt.getMonth();
var year = dt.getFullYear();
var dagensdatum = year + "-" + month + "-" + day;
var datum = this.getField("Datum");
datum.value = dagensdatum;
datum = this.getField("Datum2");
datum.value = dagensdatum;
datum = this.getField("Datum3");
datum.value = dagensdatum;
But when i run this, it prints out 11th of April and not todays date. Any ideas?
for your 2nd question I don't know why the date is not correct, but at least, you should do this :
var month = dt.getMonth();
month++;
because the getMonth() returns an int between 0 and 11. As for the day, I don't know what could cause the problem.
Edit : Have you checked your own date on your computer? Because if it is wrong it will be displayed uncorrectly in your browser. I guess you should have a date of 11th May in your computer, don't you?