Use the [`getTime` method][1] to get the time in total milliseconds since 1970-01-01, and subtract those:

    var time = new Date().getTime() - new Date(&quot;2013-02-20T12:01:04.753Z&quot;).getTime();


  [1]: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Date/getTime

This is how it should be done in typescript:

    (new Date()).valueOf() - (new Date(&quot;2013-02-20T12:01:04.753Z&quot;)).valueOf()

Better readability:

          var eventStartTime = new Date(event.startTime);
          var eventEndTime = new Date(event.endTime);
          var duration = eventEndTime.valueOf() - eventStartTime.valueOf();


In order to calculate the difference you have to put the `+` operator,

 that way `typescript` converts the dates to numbers.

    +new Date()- +new Date(&quot;2013-02-20T12:01:04.753Z&quot;)

From there you can make a formula to convert the difference to `minutes` or `hours`.



It doesn&#39;t work because `Date - Date` relies on exactly the kind of type coercion TypeScript is designed to prevent.

There is a workaround for this using the `+` prefix:

    var t = Date.now() - +(new Date(&quot;2013-02-20T12:01:04.753Z&quot;));

Or, if you prefer not to use `Date.now()`:

    var t = +(new Date()) - +(new Date(&quot;2013-02-20T12:01:04.753Z&quot;));

[See discussion here][1].

Or see Siddharth Singh&#39;s answer, below, for a more elegant solution using `valueOf()`


  [1]: https://web.archive.org/web/20170506161203/http://typescript.codeplex.com/workitem/156

    
    // TypeScript
    
    const today = new Date();
    const firstDayOfYear = new Date(today.getFullYear(), 0, 1);

    // Explicitly convert Date to Number
    const pastDaysOfYear = ( Number(today) - Number(firstDayOfYear) );

If I have a utility function `foo` that I want to be able to call from anywhere inside of my `ng-app` declaration. Is there someway I can make it globally accessible in my module setup or do I need to add it to the scope in every controller? 

Can I make a function available in every controller in angular?

How do I access the corresponding groupby dataframe in a groupby object by the key?

With the following groupby:

    rand = np.random.RandomState(1)
    df = pd.DataFrame({&#39;A&#39;: [&#39;foo&#39;, &#39;bar&#39;] * 3,
                       &#39;B&#39;: rand.randn(6),
                       &#39;C&#39;: rand.randint(0, 20, 6)})
    gb = df.groupby([&#39;A&#39;])

I can iterate through it to get the keys and groups:

    In [11]: for k, gp in gb:
                 print &#39;key=&#39; + str(k)
                 print gp
    key=bar
         A         B   C
    1  bar -0.611756  18
    3  bar -1.072969  10
    5  bar -2.301539  18
    key=foo
         A         B   C
    0  foo  1.624345   5
    2  foo -0.528172  11
    4  foo  0.865408  14

I would like to be able to access a group by its key:

    In [12]: gb[&#39;foo&#39;]
    Out[12]:  
         A         B   C
    0  foo  1.624345   5
    2  foo -0.528172  11
    4  foo  0.865408  14

But when I try doing that with `gb[(&#39;foo&#39;,)]` I get this weird `pandas.core.groupby.DataFrameGroupBy` object thing which doesn&#39;t seem to have any methods that correspond to the DataFrame I want.

The best I could think of is:

    In [13]: def gb_df_key(gb, key, orig_df):
                 ix = gb.indices[key]
                 return orig_df.ix[ix]
        
             gb_df_key(gb, &#39;foo&#39;, df)
    Out[13]:
         A         B   C
    0  foo  1.624345   5
    2  foo -0.528172  11
    4  foo  0.865408  14  

but this is kind of nasty, considering how nice pandas usually is at these things.  
What&#39;s the built-in way of doing this?

How to access pandas groupby dataframe by key

This works in Javascript

    new Date() - new Date(&quot;2013-02-20T12:01:04.753Z&quot;)

But in typescript I can&#39;t rest two new Dates

    Date(&quot;2013-02-20T12:01:04.753Z&quot;)

Don&#39;t work because paremater not match date signature

How can I calculate the time between 2 Dates in typescript

This works in Javascript
<pre><code class="hljs language-javascript">new Date() - new Date("2013-02-20T12:01:04.753Z")
</code></pre>
But in typescript I can't rest two new Dates
<pre><code class="hljs language-javascript">Date("2013-02-20T12:01:04.753Z")
</code></pre>
Don't work because paremater not match date signature

I want to convert date string to `Date` by javascript, use this code:

    var date = new Date(&#39;2013-02-27T17:00:00&#39;);
    alert(date);

`&#39;2013-02-27T17:00:00&#39;` is UTC time in JSON object from server.

But the result of above code is different between Firefox and Chrome:

Firefox returns: 

    Wed Feb 27 2013 17:00:00 GMT+0700 (SE Asia Standard Time)

Chrome returns:

    Thu Feb 28 2013 00:00:00 GMT+0700 (SE Asia Standard Time) 

It&#39;s different 1 day, the correct result I would expect is the result from Chrome.

Demo code: http://jsfiddle.net/xHtqa/2/

How can I fix this problem to get the same result from both?



new Date() works differently in Chrome and Firefox

    formatCalendarDate = function (dateTime) {
        return moment.utc(dateTime).format(&#39;LLL&#39;);
    };

It displays: &quot;28 februari 2013 09:24&quot;

But I would like to remove the time at the end. How can I do that?

I&#39;m using [Moment.js][1].

  [1]: http://momentjs.com/

How can I remove time from date with Moment.js?

I&#39;ve a GET request that sends a date in YYYY-MM-DD format to a Spring Controller.
The controller code is as follows:

    @RequestMapping(value=&quot;/fetch&quot; , method=RequestMethod.GET)
    	public @ResponseBody String fetchResult(@RequestParam(&quot;from&quot;) Date fromDate) {
    		//Content goes here
    	}

The request is sent correctly as I&#39;m checking with Firebug.
I get the error:

&gt; HTTP Status 400: The request sent by the client was syntactically incorrect.

How can I make the controller accept this format of Date? 
Please help. What am I doing wrong?

How to accept Date params in a GET request to Spring MVC Controller?

I want to add days in some date. I have a code like this: 

    DateTime endDate = Convert.ToDateTime(this.txtStartDate.Text); 
    Int64 addedDays = Convert.ToInt64(txtDaysSupp.Text); 
    endDate.AddDays(addedDays); 
    DateTime end = endDate; 
    this.txtEndDate.Text = end.ToShortDateString();

But this code is not working, days are not added! What the stupid mistake I&#39;m doing?

Datetime in C# add days

If at all possible, without JavaScript libraries or lots of clunky code I am looking for the simplest way to format a date two weeks from now in the following format:

`13th March 2013`

The code I am using is:

    var newdate = new Date(+new Date + 12096e5);
    document.body.innerHTML = newdate;


which returns the date and time two weeks from now, but like this:
Wed Mar 27 2013 21:50:29 GMT+0000 (GMT Standard Time)

Here is the code in [jsFiddle][1].

Any help would be appreciated!


  [1]: http://jsfiddle.net/CT7Fm/40/

JavaScript new Date Ordinal (st, nd, rd, th)

Does Typescript currently (or are there plans to) support the [safe navigation][1] operator of `?.`

ie:

    var thing = foo?.bar
    // same as:
    var thing = (foo) ? foo.bar : null;

Also, is there a more common name for this operator (it&#39;s incedibly hard to google for).


  [1]: http://mrhaki.blogspot.com.au/2009/08/groovy-goodness-safe-navigation-to.html

Does Typescript support the ?. operator? (And, what&#39;s it called?)

I have an array that I&#39;ve created in TypeScript and it has a property that I use as a key. If I have that key, how can I remove an item from it?

How do I remove an array item in TypeScript?

I meant to write a parameter of type `number`, but I misspelled the type, writing `Number` instead. 

On my IDE (JetBrains WebStorm) the type `Number` is written with the same color that is used for the primitive type `number`, while if I write a name of a class (known or unknown) it uses a different color, so I guess that somehow it recognizes the misspelled type as a correct/almost-correct/sort-of-correct type.
 
When I compile the code, instead of complaining for example that the compiler couldn&#39;t found a class named `Number`, TSC writes this error message: 

    Illegal property access

Does that mean that `number` and `Number` both co-exists as different types?

If this is true, which is the difference between those classes?

If this is not the case, then why it simply didn&#39;t write the same error message it displays for unknown classes (&quot;The name &#39;Number&#39; does not exist in the current scope&quot;)

This is the code:


    class Test
    {
        private myArray:string[] = [&quot;Jack&quot;, &quot;Jill&quot;, &quot;John&quot;, &quot;Joe&quot;, &quot;Jeff&quot;];

        // THIS WORKS
        public getValue(index:number):string
        {
            return this.myArray[index];
        }

        // THIS DOESN&#39;T WORK: ILLEGAL PROPERTY ACCESS
        public getAnotherValue(index:Number):string
        {
            return this.myArray[index]; 
        }
    }




Typescript primitive types: any difference between the types &quot;number&quot; and &quot;Number&quot; (is TSC case-insensitive)?

Following code can be used to create an `enum` in TypeScript:

    enum e {
    	hello = 1,
    	world = 2
    };

And the values can be accessed by: 

    e.hello;
    e.world;

How do I create an `enum` with string values?

    enum e {
    	hello = &quot;hello&quot;, // error: cannot convert string to e
    	world = &quot;world&quot;  // error 
    };





Create an enum with string values

Is it possible to export a simple function from a typescript module?

[This isn&#39;t compiling for me.][1]

    module SayHi {
        export function() {
        console.log(&quot;Hi&quot;);
      }
    }
    new SayHi();


[This workitem][2] seems to imply that you cannot but doesn&#39;t flat out say it. Is it not possible? 


  [1]: http://www.typescriptlang.org/Playground/#src=module%20SayHi%20%7B%0A%20%20%20%20export%20function%28%29%20%7B%0A%09%09console.log%28%22Hi%22%29;%0A%09%7D%0A%7D%0Anew%20SayHi%28%29;%0A
  [2]: https://typescript.codeplex.com/workitem/47

Content Type	Original Author	Original Content on Stackoverflow
Question	user2025288	View Question on Stackoverflow
Solution 1 - Date	Guffa	View Answer on Stackoverflow
Solution 2 - Date	Siddharth Singh	View Answer on Stackoverflow
Solution 3 - Date	alexalejandroem	View Answer on Stackoverflow
Solution 4 - Date	Jude Fisher	View Answer on Stackoverflow
Solution 5 - Date	altergothen	View Answer on Stackoverflow

How can I calculate the time between 2 Dates in typescript

Date Problem Overview

Date Solutions

Solution 1 - Date

Solution 2 - Date

Solution 3 - Date

Solution 4 - Date

Solution 5 - Date

How to access pandas groupby dataframe by key

Can I make a function available in every controller in angular?

Attributions