Develop Reference

Display Current date with additional 30 days of calculation - JS

I am trying to display current date by finding string and replacing with current date, its working fine, but additionally I want to display another date where if string has some comma seprated value then it will add to the current date and will display accodrdingly, So lets say if I add (,30) in string it will add 30 days additional in current date and display
var setCurrentDate = function() {
var disclaimerStr = $(".dynamic-date").html(),
currDateStr = "{currentdate}",
date = new Date(),
months = [
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"
],
currDate =
months[date.getMonth()] +
" " +
date.getDate() +
", " +
date.getFullYear(),
newDisclaimerStr;
if (disclaimerStr.indexOf(currDateStr) != -1) {
newDisclaimerStr = disclaimerStr.replace(currDateStr, currDate);
$(".dynamic-date").html(newDisclaimerStr);
}
};
setCurrentDate();
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="dynamic-date">
<b>Current Date</b> : {currentdate} <br><br>
<b>Extended Date</b> : {currentdate,30} <br><br>
</div>

Try this code :
var setCurrentDate = function() {
var disclaimerStr = $(".dynamic-date").html(),
currDateStr = "{currentdate}",
date = new Date(),
months = [
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"
],
currDate =
months[date.getMonth()] +
" " +
date.getDate() +
", " +
date.getFullYear(),
newDisclaimerStr;
if (disclaimerStr.indexOf(currDateStr) != -1) {
newDisclaimerStr = disclaimerStr.replace(currDateStr, currDate);
$(".dynamic-date").html(newDisclaimerStr);
}
var reg = new RegExp(/\{currentdate(,(\d+))\}/);
var currDateStr2 = '{currentdate,30}'; // you need to change here!
var days = parseInt(reg.exec(currDateStr2)[2], 10);
console.log(days) //30
var date2 = new Date();
date2.setDate(date2.getDate() + days);
console.log(date2) // "2019-04-27T09:13:00.789Z"
};
setCurrentDate();
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="dynamic-date">
<b>Current Date</b> : {currentdate} <br><br>
<b>Extended Date</b> : {currentdate,30} <br><br>
</div>

Coverting DATETIME string to time and date in words Javascript or jQuery

i have a datetime parameter in a string from an JSON object
like this-
datetime:"2015-04-15 09.00.00"
my goal is to convert it to:
"15 April 09:00"
(2015 can be included as well but not necessary)
After i will append in in 2 different places, date and time.
Any suggestions? Can't seem to find any good info apart from getting a plugin.

You can parse the month like the answer here:
https://stackoverflow.com/a/1643468/2498251
var monthNames = ["January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December"
];
so for your case you can make something like this:
var d = new Date("2015-04-15 09:00:00");
var day = d.getDay();
var month = monthNames[d.getMonth()];
var year = d.getYear();
var hour = d.getHours();
var min = d.getMinutes();
var fullDatetime = day + ' ' + month + ' ' + hour + ':' + min;

How to Populate An Array of Month Number In jQuery - Javascript

Can you please take a look at this demo and let me know how I can dynamically populate the number of each month for current year in jQuery or JavaScript?
var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
var daysInMonth = [];
var d = new Date();
var n = d.getMonth();
for (var i = 0; i < monthNames.length; i++) {
daysInMonth.push(d.getMonth());
}
console.log(daysInMonth);

var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
var daysInMonth = [];
for (var i = 0; i < monthNames.length; i++) {
var year = 2014;
var month = new Date(monthNames[i] + " 01 "+ year).getMonth() + 1;
daysInMonth.push(new Date(year, month, 0).getDate());
}
console.log(daysInMonth);
DEMO http://jsfiddle.net/0mj2cxmt/7/

#Sam Battat's answer works too, but for a simple snippet of code that works on any year when called you could try this:
var thisDay = new Date();
var thisYear = thisDay.getYear();
var feb29th = new Date(thisYear, 1, 29);
var febDays = ((feb29th.getMonth() === 1) ? 29 : 28);
var dayCounts = [31,febDays,31,30,31,30,31,31,30,31,30,31];
Notes:
The number of days is hard coded for all months except February since they don't change
The feb29th variable above will actually become March 1st on years that don't have 29 days (e.g. non-leap years) and thus the month won't be "1"... defaulting the number of days back to 28
Update:
After running this perf test http://jsperf.com/leap-year-check it has become apparent that the "crafty" check for a leap year performance is nowhere near as good as basic math checks.
Thus I'd consider this to be even more efficient.
var thisDay = new Date();
var thisYear = thisDay.getYear();
var febDays = 28;
if((thisYear % 4 == 0) && (thisYear % 100 != 0) || (thisYear % 400 == 0)){
febDays = 29;
}
var dayCounts = [31,febDays,31,30,31,30,31,31,30,31,30,31];

Displaying my date to a specific format

I am having a little difficulty with this.How can I display a date value to format 10 September 2014 using Javascript.
What I am doing at the moment is
var dateAdded = new Date(parseInt(user.DateAdded.substr(6)));
which gives me Wed Sep 10 2014

duplicate of How to format a JavaScript date
but Marko's accepted answer there for you:
Taken from http://www.webdevelopersnotes.com/tips/html/javascript_date_and_time.php3:
<script type="text/javascript">
<!--
var m_names = new Array("January", "February", "March",
"April", "May", "June", "July", "August", "September",
"October", "November", "December");
var d = new Date();
var curr_date = d.getDate();
var curr_month = d.getMonth();
var curr_year = d.getFullYear();
document.write(curr_date + "-" + m_names[curr_month]
+ "-" + curr_year);
//-->
</script>
You can edit the array to use Jan, Feb, Mar, etc..

Day not showing up in JS Date Script

Trying to show the date on the webpage as "Wednesday, January 22, 2014" Instead I am getting a undefined, January 22, 2014.
What am I missing?
<p>Today's date is: <script type="text/javascript">
<!--
var days = new Array("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday");
var months = new Array(
"January", "February", "March", "April",
"May", "June", "July", "August", "September",
"October", "November", "December");
var currentTime = new Date();
var month = currentTime.getMonth();
var day = currentTime.getDate();
var year = currentTime.getFullYear();
document.write(days[day] + ", " + months[month] + " " + day + ", " + year);
//-->
</script>

not that you've asked but what about using moment.js

Nevermind. Should have tried one more thing:
<p>Today's date is: <script type="text/javascript">
<!--
var days = new Array("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday");
var months = new Array(
"January", "February", "March", "April",
"May", "June", "July", "August", "September",
"October", "November", "December");
var currentTime = new Date();
var today = currentTime.getDay();
var month = currentTime.getMonth();
var day = currentTime.getDate();
var year = currentTime.getFullYear();
document.write(days[today] + ", " + months[month] + " " + day + ", " + year);
//-->
</script>