I have this JS script:
if ($('.count-down').length !== 0){
$('.count-down').countdown({
timestamp : (new Date()).getTime() + 24*60*60*1000
});
}
It provides +24 hours as 24*60*60*1000 so script starts count down from 24:00:00
I need to give this script my event date as valuable format Y.m.d H:i I.E. 2014.12.31 12:00, that it would calculate the time difference between now and add it to the code.
var difference = getTimeDifferenceFromNow('2014.12.31 12:00')
timestamp : (new Date()).getTime() + difference
Substract two Date instances, you will get the length between in millisecond.
function getTimeDifferenceFromNow(timeString) {
return new Date(timeString) - new Date();
}
getTimeDifferenceFromNow('2014.12.31 12:00') // 818501769, roughly 9 days and half in the future.
How could this work? When you substract two Date instances, their valueOf() method is called internally, which will convert them to timestamp. Then you are actually subsctracting two timestamps, finally get a number of millisecond.
EDIT
However, I was wondering why you did in that way? If you want the timestamp of a given date/time, why don't you just instantiate it and grab its timestamp?
new Date('2014.12.31 12:00').getTime() // 1419998400000
This was the final solution:
var eventdate = new Date("January 1, 2015 1:00:00").getTime();
if ($('.count-down').length !== 0){
$('.count-down').countdown({
timestamp : eventdate
});
}
Related
I have a code where I try to set date 20 days back from current date on server. I have used a variable(say dateRange) in javascript to get current date. But on using the same variable second time for setDate() function value of dateRange is changed to epoch from date. I know I can convert epoch to date and proceed but is there a way to stop this automatic conversion.
var dateRange=new Date(currentDate);
dateRange = dateRange.setDate(dateRange.getDate() - 20);
setDate modifies the date object, and returns the epoch value. Just don't save the epoch value in dateRange, so you can use the date object after modifying it:
var currentDate = new Date();
var dateRange = new Date(+currentDate);
console.log(dateRange.toISOString());
dateRange.setDate(dateRange.getDate() - 20);
console.log(dateRange.toISOString());
Side note: Copying a date by doing var dateRange = new Date(currentDate); is/was unreliable on some browsers. In the above, I've changed it to var dateRange = new Date(+currentDate); (note the +, converting the date to its epoch value), which is reliable.
Internally dates are stored as milliseconds from the epoch date.
To achieve what you are trying to do you can subtract the number of milliseconds that corresponds to 20 days:
var currentDate = "2019-07-29T07:14:57.269Z";
var dateRange = new Date(currentDate);
var pastDate = new Date(dateRange - 1000 * 60 * 60 * 24 * 20);
console.log('current', currentDate);
console.log('20 days ago', pastDate);
anyway if you are doing a lot of date/time manipulations in your app i suggest you to use this library: https://momentjs.com/
I have this script that makes a button redirect to a whatsapp page, on the URL (a href) I need to insert the number that's gonna be contacted.
What I need to do is each day a different number fills this URL.
Example:
day1 - phonen1,
day2 - phonen2,
...,
day 13 - phonen13,
//(starts over)
day14 - phonen1,
day15 - phonen2,
...
<a id="whatsapp" target="_blank" href="https://api.whatsapp.com/send?phone=5519997820734">Link</a>
<script>
phones= ["phonen1", "phonen2", ..., "phonen13"];
document.getElementById("whatsapp").href = "https://api.whatsapp.com/send?phone=5519"+ phones[i] +"";
</script>
you can use the date object with for loop like this:
<a id="whatsapp" target="_blank" href="https://api.whatsapp.com/send?phone=5519997820734">Link</a>
<script>
phones= ["phonen1", "phonen2", ..., "phonen13"];
var d = new Date();
var todayDate = d.getDate();
for (var i = todayDate; i > 13; i= i-13) {
todayDate = todayDate - 13;
}
document.getElementById("whatsapp").href = "https://api.whatsapp.com/send?phone=5519"+phones[i] + todayDate;
</script>
Simple Answer:
You can do this using a Date to count the number of days since the unix epoch, and mod that count by the length of your phones array to get an index that moves to the next item every 24 hours:
let phones = ["phonen1", "phonen2", "phonen3", "phonen4"];
const ms_per_day = 24 * 60 * 60 * 1000;
// (new Date()).getTime() gets the number of ms since 1 January 1970 00:00:00 UTC
// we divide by ms_per_day and floor to get the number of 24-hour cycles (this will increment each UTC day)
let days_since_epoch = Math.floor((new Date()).getTime() / ms_per_day);
// we mod by the length of phones to get a number in the range [0, phones.length)
let phones_index = days_since_epoch % phones.length;
document.getElementById("whatsapp").href = "https://api.whatsapp.com/send?phone=5519" + phones[phones_index];
console.log("Set link to", document.getElementById("whatsapp").href);
<a id="whatsapp" target="_blank" href="https://api.whatsapp.com/send?phone=5519997820734"> Link </a>
Caveats:
Working with time is complicated. The above method doesn't get the number of days exactly:
Due to the differing lengths of days (due to daylight saving changeover), months and years, expressing elapsed time in units greater than hours, minutes and seconds requires addressing a number of issues and should be thoroughly researched before being attempted.
...and the crossover time is in UTC anyway, so it's non-obvious when the above code will switch numbers (it won't be at midnight). But it will do so once every 24 hours, which should be sufficient for the use case described in the post.
One other caveat is that the number won't actually change until the user refreshes the page and reruns the script.
Use the date object to create an index into your array
<a id="whatsapp" target="_blank" href="https://api.whatsapp.com/send?phone=5519997820734">Link</a>
<script>
var phones= ["phone1","phone2","phone3","phone4","phone5","phone6","phone7","phone8","phone9","phone10","phone11","phone12","phone13","phone14"];
var startOfDay1 = new Date('July 1, 2018 00:00:00');//be aware this is the client timezone
var diffFromNow = Date.now() - startOfDay1.getTime();//get the difference in ms between now and midnight of "day 1"
console.log(diffFromNow);
var diffFromNowDays = diffFromNow/(24*60*60*1000);//turn that into a day value
var daynum = Math.floor(diffFromNowDays % 14);//constrain to 14 days
console.log(daynum);//zero based index
document.getElementById("whatsapp").href = "https://api.whatsapp.com/send?phone=5519"+ phones[daynum] +"";
</script>
Ollin's answer is great, but you can use local midnight as follows if you wish. Use the remainder operator % with the number of whole days since a particular point in time, any epoch will do.
If you want to do the changeover at midnight local time, then use local midnight for the epoch and current day. Use Math.round to remove daylight saving effects.
The following will change the value returned from the array at local 00:00:00.001 each day:
// Number of whole local days since date to today
function daysDiff(date) {
// Copy date, set to start of day
var d = new Date(+date);
d.setHours(0,0,0,0);
// Get start of current day
var e = new Date();
e.setHours(0,0,0,0);
// Return whole day count
return Math.round((e - d)/8.64e7);
}
// Select item from array based on number of whole days
// from epoch to today. Default is 1 July 2018
function getFromArray(array, epoch) {
if (!epoch) {
// If not provided, use 1 July 2018
epoch = new Date(2018,6,1);
}
var d = daysDiff(epoch);
return array[d % array.length];
}
var nums = [1,2,3,4,5,6,7,8,9,10,11,12,13,14];
// On local date 12 July 2018 returns 12
console.log(getFromArray(nums));
I had two ical format timestamps and I want to convert them to normal time first and then to unix time.
Here this is the function I've been using to convert normal time to unix timestamp:
var normal_to_unix = function (date_string) {
var date = new Date(date_string);
return date.getTime() / 1000;
}
This function is fine since date is already in UTC and I need not do any conversions.
Now this is the function I've been using to convert ical time to unix time. The ical time in my case is like "20180603T150000Z".
var ics_to_unix = function (ics_string) {
var year = ics_string.slice(0, 4);
var month = ics_string.slice(4, 6);
var date = ics_string.slice(6, 8);
var hours = ics_string.slice(9, 11);
var minutes = ics_string.slice(11, 13);
var seconds = ics_string.slice(13, 15);
var milliseconds = 0;
console.log(year, month, date, hours, minutes, seconds, milliseconds); // This is example output 2018 06 03 15 00 00 0
return normal_to_unix((new Date(year, month, date, hours, minutes, seconds, milliseconds)).toDateString())
}
Now the problem is I'm getting the same unix time for "20180603T150000Z" and "20180603T160000Z" which are supposed to give different timestamps and it is 1530576000 for both of them.
Is there anything that I'm missing ? Thanks in advance.
Please have a look at this for live example
Several points here:
The toDateString() method returns the date portion of a Date object in human readable form in American English. For your example it is `Tue Jul 03 2018', perhaps that is not what you want.
new Date creates date in your local timezone, which could play well if you use it together with toString(), which will also return the string for date in your local timezone. But it will be subject to daylight saving changes, so I'd avoid using that method.
Another thing I'd like to avoid converting back and forth between strings and dates, since it does a lot of unnecessary computations.
I'd suggest to use the following:
var ics_to_unix = function (ics_string) {
var year = parseInt(ics_string.slice(0, 4));
var month = parseInt(ics_string.slice(4, 6)) - 1; // Jan is 0
var date = parseInt(ics_string.slice(6, 8));
var hours = parseInt(ics_string.slice(9, 11));
var minutes = parseInt(ics_string.slice(11, 13));
var seconds = parseInt(ics_string.slice(13, 15));
return Date.UTC(year, month, date, hours, minutes, seconds) / 1000;
}
I have added explicit conversion of strings to numbers, adjusted the month to match what is used in javascript and also removed the extra call.
Good days guys. I have this nice and clean code for a running clock.
<script type="text/javascript">
function DisplayTime(){
if (!document.all && !document.getElementById)
return
timeElement=document.getElementById? document.getElementById("curTime"): document.all.tick2
var CurrentDate=new Date()
var hours=CurrentDate.getHours()
var minutes=CurrentDate.getMinutes()
var seconds=CurrentDate.getSeconds()
var DayNight="PM"
if (hours<12) DayNight="AM";
if (hours>12) hours=hours-12;
if (hours==0) hours=12;
if (minutes<=9) minutes="0"+minutes;
if (seconds<=9) seconds="0"+seconds;
var currentTime=hours+":"+minutes+":"+seconds+" "+DayNight;
timeElement.innerHTML="<font style='font-family:Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800&subset=latin,cyrillic-ext,latin-extfont-size:14px;color:#fff;'>"+currentTime+"</b>"
setTimeout("DisplayTime()",1000)
}
window.onload=DisplayTime
</script>
My only problem is it's based the system time. How can I set the timezone so that it will display the correct time based on the timezone specified?
There's nothing built into the JavaScript Date object that handles any timezones other than local (system) time and UTC.
You can do it by giving your Date instance the wrong time, using the delta between one of those timezones (local or UTC) and the time zone you want to use. It's easier if you use UTC.
So for instance, say we want our time in GMT+01:00:
var dt = new Date();
dt.setTime(dt.getTime() + (60 * 60 * 1000));
// ^^^^^^^^^^^^^^---- one hour in milliseconds,
// which is our offset from UTC/GMT
var hours = dt.getUTCHours(); // Use UTC methods to get time
var minutes = dt.getUTCMinutes();
var seconds = dt.getUTCSeconds();
Time stuff, particularly with timezones, is hard. You might look at using a library for it, although for just this sort of clock that would be overkill. One good library is MomentJS (which has a timezone add-on).
You can use getTimezoneOffset method of the Date object. It gives you the timezone offset, according to your timezone in minutes.
So in order to get the current time in UTC (+0 timezone) you can do something of the sort:
var tzOffset = CurrentDate.getTimezoneOffset();
// some timezones are not set hours, so we must calculate the minutes
var minutesOffset = parseInt(tzOffset%60,10);
// the offset hours for the timezone
var hoursOffset = parseInt(tzOffset/60, 10);
Then you need to do some math in your code to account for the offset:
var hours = CurrentDate.getHours() + hoursOffset;
var minutes = CurrentDate.getMinutes() + minutesOffset;
This would account for your timezone. If you want to calculate another timezone, that you specify, change the tzOffset above to show your timezone.
var tzOffset = CurrentDate.getTimezoneOffset() + TIMEZONE_HOURS*60;
TIMEZONE_HOURS is the timezone in hours you want, e.g. if you want UTC+3, you must set TIMEZONE_HOURS to 3.
As a whole timezones are a bit complicated task because they change a lot and there are some caveats with them. If you want to dwell more into this, check this answer in another question on SO
I have implemented your working code by adding one more function to obtain what you want. See this will help
function DisplayTime(timeZoneOffsetminutes){
if (!document.all && !document.getElementById)
return
timeElement=document.getElementById? document.getElementById("curTime"): document.all.tick2
var requiredDate=getTimeZoneTimeObj(timeZoneOffsetminutes)
var hours=requiredDate.h;
var minutes=requiredDate.m;
var seconds=requiredDate.s;
var DayNight="PM";
if (hours<12) DayNight="AM";
if (hours>12) hours=hours-12;
if (hours==0) hours=12;
if (minutes<=9) minutes="0"+minutes;
if (seconds<=9) seconds="0"+seconds;
var currentTime=hours+":"+minutes+":"+seconds+" "+DayNight;
timeElement.innerHTML="<font style='font-family:Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800&subset=latin,cyrillic-ext,latin-extfont-size:14px;color:#fff;'>"+currentTime+"</b>"
setTimeout("DisplayTime(-330)",1000)
}
window.onload=DisplayTime(-330);
function getTimeZoneTimeObj(timeZoneOffsetminutes){
var localdate = new Date()
var timeZoneDate = new Date(localdate.getTime() + ((localdate.getTimezoneOffset()- timeZoneOffsetminutes)*60*1000));
return {'h':timeZoneDate.getHours(),'m':timeZoneDate.getMinutes(),'s':timeZoneDate.getSeconds()};
}
#curTime{
background-color:#000;
}
<div id="curTime"></div>
visit this link as a reference
example:
var x = new Date();
var currentTimeZoneOffsetInHours = x.getTimezoneOffset() / 60;
You can try using moment.js
It is very nice library which handles timezones too.
I have created a small function that i need on my site successfully in php. But i now realise i actually need this in javascript or jquery as PHP will only excute this code on load.. i need this function to work with onchange on a select. The code below is my function.. Can anyone point out where i start to convert this into js/jquery like code:
function setTrnTime ($hr, $journeyTime){
date_default_timezone_set('GMT');
//convert current hour to time format hour
$currentHour = (date("H", mktime($hr)));
// Journey time in hours
$journey = $journeyTime
$journey = $journey/60; // Get hours
$journey = ceil($journey); // Round off to next hour i.e. 3 hours 20mins is now 4 hours
// New Hours
$NewHour = (date("H", mktime($journey)));
$Newhour = $NewHour*60*60; // convert to seconds
// Final hour is Current Hour - JourneyTime (Hours)
$trnHour = (date('H', mktime($currentHour-$NewHour)));
return $trnHour;
}
With the code above, if i pass two values 06, 60: that would mean my answer would be 05. e.g. 06 is 6am. 60 is 60mins.. so 6am - 60mins = 5am.
You can do the same in javascript using the Date object, see info here
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date
EDITED: Added some code, also not even using the Date object.
But do you need something that complex, doesn't the following do what you are after with less steps.
http://jsfiddle.net/WWTDc/
If hr is a Date object, then it's very simple. Otherwise you can create a Date object and set its hour:
//! \param[in] hr Date object or hour (0--23)
//! \param[in] journeyTime journey time in minutes.
function setTrnTime(hr,journeyTime){
var end;
if(typeof(hr) === 'number'){
end = new Date();
end.setHours(hr);
}
else
end = hr;
return (new Date(end - journeyTime*60*1000)).getHours();
}
This will return the hour (demonstration).
See here for information about Date object in JavaScript.