Convert Time Stamp to Date Inside Angular Expression Like {{New Date(Timestamp)}}

convert time stamp to Date inside angular expression like {{new Date(timestamp)}}

Because angular expressions do not accept arbitrary Javascript code, including creating new objects. What you are looking for is called angular filters, they were specifically designed for this case.

So instead of

{{new Date(elem.timestamp)}}

you should write

{{elem.timestamp | date: 'yyyy-MM-dd'}}

More info on the date filter can be found here. More on filters, in general, can be found here.

Convert timestamp to date using Angular 2 pipes

As mentioned by @Perry you will need to provide the date in milliseconds. From the Angular 2 reference for date we have:

expression is a date object or a number (milliseconds since UTC epoch)
or an ISO string

So it can be simply be:

{{load.loadDate * 1000 | date}}

How do you get a timestamp in JavaScript?

Short & Snazzy:

+ new Date()

A unary operator like plus triggers the valueOf method in the Date object and it returns the timestamp (without any alteration).

Details:

On almost all current browsers you can use Date.now() to get the UTC timestamp in milliseconds; a notable exception to this is IE8 and earlier (see compatibility table).

You can easily make a shim for this, though:

if (!Date.now) {
    Date.now = function() { return new Date().getTime(); }
}

To get the timestamp in seconds, you can use:

Math.floor(Date.now() / 1000)

Or alternatively you could use:

Date.now() / 1000 | 0

Which should be slightly faster, but also less readable.

(also see this answer or this with further explaination to bitwise operators).

I would recommend using Date.now() (with compatibility shim). It's slightly better because it's shorter & doesn't create a new Date object. However, if you don't want a shim & maximum compatibility, you could use the "old" method to get the timestamp in milliseconds:

new Date().getTime()

Which you can then convert to seconds like this:

Math.round(new Date().getTime()/1000)

And you can also use the valueOf method which we showed above:

new Date().valueOf()

Timestamp in Milliseconds

var timeStampInMs = window.performance && window.performance.now && window.performance.timing && window.performance.timing.navigationStart ? window.performance.now() + window.performance.timing.navigationStart : Date.now();

console.log(timeStampInMs, Date.now());

Find a time slot which can accommodate a new time stamp and calculate frequency

You can assign the index to a particular time slot. Then we can convert an incoming time to the index.

An index could be calculated by how many "slots" proceeds the particular time, sou we could divide the time in minutes by 15 to get the index.

[
    "00:00-00:15", // 0th -> index = 0
    "00:15-00:30", // 1st -> index = 1
    .
    .
    .
    "11:15-11:30", // 93th
    "11:30-11:45", // 94th
    "11:45-00:00" // 95th -> index = 95
]

const indexToTime = (index) => {
  const hour = Math.floor(15 * index / 60) % 24
  const minute = (15 * index) % 60
  const h = `${hour}`.padStart(2, 0)
  const m = `${minute}`.padStart(2, 0)
  const time = `${h}:${m}`
  return time
}

const timeToIndex = (time) => {
  const [hour, minute] = time.split(':')
  const [h, m] = [parseInt(hour), parseInt(minute)]
  const index = hour * 4 + Math.floor(minute / 15)
  return index
}
const slots = [...Array(24 * 60 / 15)].map((_, i) => `${indexToTime(i)}-${indexToTime(i+1)}`)
console.log('slots =', slots)
const records = ['20:47 apple', '20:18 apple', '20:17 bananas', '20:43 cake', '20:18 bananas', '20:31 cake', '20:30 cake', '20:40 cake', '20:39 cake', '20:49 apple', '20:54 egg', '20:50 apple']
console.log('records =', records)

const stats = []
records.forEach(record => {
  const [time, item] = record.split(' ')
  const index = timeToIndex(time)
  if (!stats[index]) {
    stats[index] = {[item]: 1}
  } else if(!stats[index][item]) {
    stats[index][item] = 1
  } else {
    stats[index][item]++
  }
})

console.log('stats =', stats)

const statsRecords = slots.map((time, index) => ({ time, stats: stats[index] }))
console.log('statsRecords =', statsRecords)

const display = (statsRecords) => {
  return statsRecords.map(({ time, stats = {} }) => `${time} ${Object.entries(stats).map(([item, count]) => `${item} ${count}`).join(', ')}`).join('\n')
}

console.log(display(statsRecords))

How to reverse time stamp using javascript/Angular.js

You are using angular. So please try with using $filter

   $scope.timestamp =  '2016-12-16 07:02:15 am'
   $scope.originalStamp = $filter('date')
                          (new Date($scope.timestamp.replace("-","/")),'dd-MM-yyyy HH:mm:ss a');

Updated Demo

here is the full code

<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<body>

<div ng-app="myApp" ng-controller="datCtrl">

<p> {{originalStamp}} </p>

</div>

<script>
var app = angular.module('myApp', []);
app.controller('datCtrl', function($scope,$filter) {

   $scope.timestamp =  '2016-12-16 07:02:15 am'
  $scope.originalStamp = $filter('date')(new Date($scope.timestamp.replace("-","/")),'dd-MM-yyyy HH:mm:ss a');

});
</script>

<p>The date filter formats a date object to a readable format.</p>

</body>
</html>

Format Date time in AngularJS

v.Dt is likely not a Date() object.

See http://jsfiddle.net/southerd/xG2t8/

but in your controller:

scope.v.Dt = Date.parse(scope.v.Dt);

Convert Time Stamp to Date Inside Angular Expression Like {{New Date(Timestamp)}}