{"id":13381,"date":"2011-07-08T00:01:00","date_gmt":"2011-07-08T00:01:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2011\/07\/08\/use-powershell-to-get-the-number-of-the-week-of-the-year\/"},"modified":"2011-07-08T00:01:00","modified_gmt":"2011-07-08T00:01:00","slug":"use-powershell-to-get-the-number-of-the-week-of-the-year","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/use-powershell-to-get-the-number-of-the-week-of-the-year\/","title":{"rendered":"Use PowerShell to Get the Number of the Week of the Year"},"content":{"rendered":"

Summary<\/b>: Learn how to use Windows PowerShell to easily get the number of the week of the year.<\/p>\n

Microsoft Scripting Guy, Ed Wilson, is here. It seems that at times things appear to be too hard. At other times, things that I figure might be too hard, end up being super simple. I guess this is why I was never that good at project estimation tasks. A case in point is the solar collector that I decided to build for our swimming pool. The first task is to build the frame to support the collectors, then it needs a little plumbing to tie it into the pool. I figured the entire task could be accomplished in one weekend. Six weeks later, the frame itself is not even completed—and that is with Dr. Scripto’s help. The frame and Dr. Scripto appear in the following photo.<\/p>\n

\"Photo<\/a><\/p>\n

Today I decided that I needed to know the number of the week of the year. For example, is this the 23rd<\/sup> week of the year or what? The reason is that I am trying to be 30 days ahead with the Hey! Scripting Guy Blog by the time that December rolls around. Because I publish a new blog every single day, it means that if I want to take a week off, I need to be at least 10 days ahead. This is because I do not like to write, edit, and publish a blog all in the same day. Plus the fact that when I come back from a week of vacation, it takes several days just to get caught up on meeting requests, email, and phone messages. Therefore, I do not want to worry about a Hey! Scripting Guy blog as well when I return from a holiday. <\/p>\n

So with all the normal days off in December and in January, coupled with taking a couple weeks of holiday with the Scripting Wife, I always like to be 30 days ahead by the time that December 1 rolls around. This buffer also gives me time to begin working on Scripting Games events, which takes an awful lot of work as well. <\/p>\n

At first I figured that I should be able to get the week of the year by using Get-Date<\/b>. I knew there was the DayOfYear<\/b> property, so I figured there might be a WeekOfYear<\/b> property as well. Unfortunately, such was not the case. The Get-Member<\/b> command and its associated output are shown here.<\/p>\n

\n

PS C:\\Users\\ed> get-date | gm<\/span><\/span><\/span><\/p>\n

 <\/span><\/span><\/span><\/p>\n

   <\/span><\/span>TypeName: System.DateTime<\/span><\/span><\/span><\/span><\/p>\n

 <\/span><\/span><\/span><\/p>\n

Name                 <\/span>MemberType     <\/span>Definition<\/span><\/span><\/span><\/p>\n

—-                 <\/span>———-     <\/span>———-<\/span><\/span><\/span><\/p>\n

Add                  <\/span>Method         <\/span>System.DateTime Add(System.TimeSpan value)<\/span><\/span><\/span><\/p>\n

AddDays              <\/span>Method         <\/span>System.DateTime AddDays(double value)<\/span><\/span><\/span><\/p>\n

AddHours             <\/span>Method         <\/span>System.DateTime AddHours(double value)<\/span><\/span><\/span><\/p>\n

AddMilliseconds      <\/span>Method         <\/span>System.DateTime AddMilliseconds(double value)<\/span><\/span><\/span><\/p>\n

AddMinutes           <\/span>Method         <\/span>System.DateTime AddMinutes(double value)<\/span><\/span><\/span><\/p>\n

AddMonths            <\/span>Method         <\/span>System.DateTime AddMonths(int months)<\/span><\/span><\/span><\/p>\n

AddSeconds           <\/span>Method         <\/span>System.DateTime AddSeconds(double value)<\/span><\/span><\/span><\/p>\n

AddTicks             <\/span>Method         <\/span>System.DateTime AddTicks(long value)<\/span><\/span><\/span><\/p>\n

AddYears             <\/span>Method         <\/span>System.DateTime AddYears(int value)<\/span><\/span><\/span><\/p>\n

CompareTo            <\/span>Method         <\/span>int CompareTo(System.Object value), int CompareTo(System.DateTime value)<\/span><\/span><\/span><\/p>\n

Equals               <\/span>Method         <\/span>bool Equals(System.Object value), bool Equals(System.DateTime value)<\/span><\/span><\/span><\/p>\n

GetDateTimeFormats   <\/span>Method         <\/span>string[] GetDateTimeFormats(), string[] GetDateTimeFormats(System.IFormatProvide…<\/span><\/span><\/span><\/p>\n

GetHashCode          <\/span>Method         <\/span>int GetHashCode()<\/span><\/span><\/span><\/p>\n

GetType              <\/span>Method         <\/span>type GetType()<\/span><\/span><\/span><\/p>\n

GetTypeCode          <\/span>Method         <\/span>System.TypeCode GetTypeCode()<\/span><\/span><\/span><\/p>\n

IsDaylightSavingTime Method         <\/span>bool IsDaylightSavingTime()<\/span><\/span><\/span><\/p>\n

Subtract             <\/span>Method         <\/span>System.TimeSpan Subtract(System.DateTime value), System.DateTime Subtract(System…<\/span><\/span><\/span><\/p>\n

ToBinary             <\/span>Method         <\/span>long ToBinary()<\/span><\/span><\/span><\/p>\n

ToFileTime           <\/span>Method         <\/span>long ToFileTime()<\/span><\/span><\/span><\/p>\n

ToFileTimeUtc        <\/span>Method         <\/span>long ToFileTimeUtc()<\/span><\/span><\/span><\/p>\n

ToLocalTime          <\/span>Method         <\/span>System.DateTime ToLocalTime()<\/span><\/span><\/span><\/p>\n

ToLongDateString     <\/span>Method         <\/span>string ToLongDateString()<\/span><\/span><\/span><\/p>\n

ToLongTimeString     <\/span>Method         <\/span>string ToLongTimeString()<\/span><\/span><\/span><\/p>\n

ToOADate             <\/span>Method         <\/span>double ToOADate()<\/span><\/span><\/span><\/p>\n

ToShortDateString    <\/span>Method         <\/span>string ToShortDateString()<\/span><\/span><\/span><\/p>\n

ToShortTimeString    <\/span>Method         <\/span>string ToShortTimeString()<\/span><\/span><\/span><\/p>\n

ToString             <\/span>Method         <\/span>string ToString(), string ToString(string format), string ToString(System.IForma…<\/span><\/span><\/span><\/p>\n

ToUniversalTime      <\/span>Method         <\/span>System.DateTime ToUniversalTime()<\/span><\/span><\/span><\/p>\n

DisplayHint          <\/span>NoteProperty   <\/span>Microsoft.PowerShell.Commands.DisplayHintType DisplayHint=DateTime<\/span><\/span><\/span><\/p>\n

Date                 <\/span>Property       <\/span>System.DateTime Date {get;}<\/span><\/span><\/span><\/p>\n

Day                  <\/span>Property       <\/span>System.Int32 Day {get;}<\/span><\/span><\/span><\/p>\n

DayOfWeek            <\/span>Property       <\/span>System.DayOfWeek DayOfWeek {get;}<\/span><\/span><\/span><\/p>\n

DayOfYear            <\/span>Property       <\/span>System.Int32 DayOfYear {get;}<\/span><\/span><\/span><\/p>\n

Hour                 <\/span>Property       <\/span>System.Int32 Hour {get;}<\/span><\/span><\/span><\/p>\n

Kind                 <\/span>Property       <\/span>System.DateTimeKind Kind {get;}<\/span><\/span><\/span><\/p>\n

Millisecond          <\/span>Property       <\/span>System.Int32 Millisecond {get;}<\/span><\/span><\/span><\/p>\n

Minute               <\/span>Property       <\/span>System.Int32 Minute {get;}<\/span><\/span><\/span><\/p>\n

Month                <\/span>Property       <\/span>System.Int32 Month {get;}<\/span><\/span><\/span><\/p>\n

Second               <\/span>Property       <\/span>System.Int32 Second {get;}<\/span><\/span><\/span><\/p>\n

Ticks                <\/span>Property       <\/span>System.Int64 Ticks {get;}<\/span><\/span><\/span><\/p>\n

TimeOfDay            <\/span>Property       <\/span>System.TimeSpan TimeOfDay {get;}<\/span><\/span><\/span><\/p>\n

Year                 <\/span>Property       <\/span>System.Int32 Year {get;}<\/span><\/span><\/span><\/p>\n

DateTime             <\/span>ScriptProperty System.Object DateTime {get=if ((& { Set-StrictMode -Version 1; $this.DisplayHin…<\/span><\/span><\/span><\/p>\n

 <\/span><\/span><\/span><\/p>\n

PS C:\\Users\\ed> <\/span><\/span><\/span><\/p><\/blockquote>\n

“Major bummer,” I thought. Now I figure it is going to be pain to retrieve the information. I open up MSDN in my Internet Explorer 9 browser, and begin searching. It does indeed look like it will be a pain. I have to create calendar rules, calendar types, and all kinds of culture specific things<\/a> (such as when the first day of the week appears, and how to determine the first week of the year). Ugh, I hate messing around with all that stuff. Whine whine whine whine whine<\/i> (as the Scripting Wife would say). <\/p>\n

But I am positive that I have seen a week of the year before, and it did not involve a lot of messy .NET Framework programming. I decided to look up the help on Get-Date<\/a> to be on the safe side before I started all that work. In the –uformat<\/b> section I found my answer…I can use the %V<\/b> <\/i>value for the UFormat<\/i> parameter. This is shown here where the command tells me that I am in the 23rd<\/sup> week as I write this Hey! Scripting Guy blog.<\/p>\n

\n

PS C:\\Users\\ed> get-date -UFormat %V<\/span><\/span><\/span><\/p>\n

23<\/span><\/span><\/span><\/p>\n

PS C:\\Users\\ed><\/span><\/span><\/span><\/p>\n<\/blockquote>\n

I decided to write a quick function to return a custom DateTime<\/b> object. At first, I was only going to return the week of the year, but hey, I might want to know what that week of the year is associated with, and so I incorporated a call to the Add-Member<\/b> Windows PowerShell cmdlet. The complete Get-ExtendedDate<\/b> function is shown here. <\/p>\n

Get-ExtendedDate Function<\/b><\/p>\n

\n

function Get-ExtendedDate<\/span><\/span><\/span><\/p>\n

{<\/span><\/span><\/span><\/p>\n

 <\/span><\/span>$a = get-date<\/span><\/span><\/span><\/span><\/p>\n

  <\/span><\/span>add-member -MemberType scriptmethod -name GetWeekOfYear `<\/span><\/span><\/span><\/span><\/p>\n

     <\/span><\/span>-value {get-date -uformat %V} -inputobject $a <\/span><\/span><\/span><\/span><\/p>\n

 <\/span><\/span>$a<\/span><\/span><\/span><\/span><\/p>\n

 <\/span><\/span>} #end function Get-ExtendedDate<\/span><\/span><\/span><\/span><\/p>\n<\/blockquote>\n

In the Get-ExtendedDate<\/b> function, I first obtain a copy of the System.DateTime<\/b> object by calling the Get-Date<\/b> cmdlet. I store the returned object in the $a<\/b> variable. This is shown here.<\/p>\n

\n

$a = get-date<\/span><\/span><\/span><\/p>\n<\/blockquote>\n

The object stored in the $a<\/b> variable is the base object upon which I will add an additional member. There are several different types of members to add to an object—I am adding a ScriptMethod<\/b> member because I want to perform a calculation when the member is called. To use the Add-Member<\/b> Windows PowerShell cmdlet, I specify the type of member to add, a name for the member, how the member value is obtained, and an object upon which to add the member. The command is shown here. <\/p>\n

\n

add-member -MemberType scriptmethod -name GetWeekOfYear `<\/span><\/span><\/span><\/p>\n

     <\/span><\/span>-value {get-date -uformat %V} -inputobject $a<\/span><\/span><\/span> <\/span><\/span><\/span><\/p>\n<\/blockquote>\n

The last thing I need to do is to return the modified object that is stored in the $a<\/b> variable, and close my curly brackets as shown here.<\/p>\n

\n

$a<\/span><\/span><\/span><\/p>\n

 <\/span><\/span>} #end function Get-ExtendedDate<\/span><\/span><\/span><\/span><\/p><\/blockquote>\n

When I call the Get-ExtendedDate<\/b> function, a standard DateTime<\/b> object is returned. Because it is a standard DateTime<\/b>, the display specifier returns the standard display. This is shown in the following image.<\/p>\n

\"Image<\/a><\/p>\n

If I pipe the results of the function to the Get-Member<\/b> cmdlet, I can tell that the additional member is added to the DateTime<\/b> object. The command to do this is shown here.<\/p>\n

\n

Get-ExtendedDate | get-member<\/span><\/span><\/span><\/p>\n<\/blockquote>\n

The command and its associated output are shown in the following image.<\/p>\n

\"Image<\/a><\/p>\n

To access the new ScriptMethod<\/b>, I have a number of options. The one I have a tendency to use is to call the method directly from the function by using a dotted notation. It sounds more complicated than it is. I use a pair of parentheses to surround the function and then call the method. The only hard part is to remember that I created a method, and therefore an empty pair of parentheses is required at the end of the method name. This is shown here.<\/p>\n

\n

PS C:\\Users\\ed> (Get-ExtendedDate).getWeekOfYear()<\/span><\/span><\/span><\/p>\n

23<\/span><\/span><\/span><\/p>\n<\/blockquote>\n

Of course, one can always store the resulting object into a variable, and call the method that way. This is shown here.<\/p>\n

\n

PS C:\\Users\\ed> $b = Get-ExtendedDate<\/span><\/span><\/span><\/p>\n

PS C:\\Users\\ed> $b.GetWeekOfYear()<\/span><\/span><\/span><\/p>\n

23<\/span><\/span><\/span><\/p>\n<\/blockquote>\n

In fact, it is because you can store the object in a variable that I decided to add my ScriptMethod<\/b> to the DateTime<\/b> object in the first place. I can use any of the properties and methods of a normal<\/i> DateTime<\/b> object in addition to calling my custom ScriptMethod<\/b>. For example, I might want to do something like the following:<\/p>\n

\n

“Today is $($b.ToShortDateString())”<\/span><\/span><\/span><\/p>\n

“There are $(365 – $($b.DayOfYear)) days left in the year.”<\/span><\/span><\/span><\/p>\n

“This means there are $(52 – $($b.GetWeekOfYear())) weeks left in the year.”<\/span><\/span><\/span><\/p>\n<\/blockquote>\n

In short, I have complete access to the DateTime<\/b> object, and I have access to my new ScriptMethod <\/b>as well. Dude, that makes for a cool solution. By the way, here are the previous commands and their associated output.<\/p>\n

\"Image<\/a><\/p>\n

Well, that is all there is to extending the DateTime<\/b> object to include the GetWeekOfYear<\/strong> ScriptMethod<\/b>. Join me tomorrow for more Windows PowerShell goodness. <\/p>\n

I invite you to follow me on Twitter<\/a> and Facebook<\/a>. If you have any questions, send email to me at scripter@microsoft.com<\/a>, or post your questions on the Official Scripting Guys Forum<\/a>. See you tomorrow. Until then, peace.<\/p>\n

Ed Wilson, Microsoft Scripting Guy<\/b><\/p>\n","protected":false},"excerpt":{"rendered":"

Summary: Learn how to use Windows PowerShell to easily get the number of the week of the year. Microsoft Scripting Guy, Ed Wilson, is here. It seems that at times things appear to be too hard. At other times, things that I figure might be too hard, end up being super simple. I guess this […]<\/p>\n","protected":false},"author":595,"featured_media":87096,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[13,3,4,45],"class_list":["post-13381","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripting","tag-dates-and-times","tag-scripting-guy","tag-scripting-techniques","tag-windows-powershell"],"acf":[],"blog_post_summary":"

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