{"id":17531,"date":"2010-08-05T00:01:00","date_gmt":"2010-08-05T00:01:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2010\/08\/05\/manipulating-dates-returned-by-windows-management-instrumentation-wmi\/"},"modified":"2010-08-05T00:01:00","modified_gmt":"2010-08-05T00:01:00","slug":"manipulating-dates-returned-by-windows-management-instrumentation-wmi","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/manipulating-dates-returned-by-windows-management-instrumentation-wmi\/","title":{"rendered":"Manipulating Dates Returned by Windows Management Instrumentation (WMI)"},"content":{"rendered":"

 \n\"Hey,\nHey, Scripting Guy! I need to understand how to work with dates that I receive from Windows Management Instrumentation (WMI<\/a>). I remember in VBScript I had to use a function I got from the Scripting Guys that did string manipulation to convert the WMI date to a “normal” date. I guess that is okay, but I had no idea how that function worked or how to correct things when it did not work properly. I have been reading your Hey, Scripting Guy! Blog<\/a> posts this week about dates, and I have yet to see you address this issue. Is it because it is too hard, and you are going to do the old two-step shuffle?\n— EA\n \n\"Hey,\nHello EA,\nMicrosoft Scripting Guy Ed Wilson here. As a famous twentieth century philosopher once said, “I can’t dance<\/a>”; therefore, I do not know how to do the old two-step<\/a> shuffle. Or the Ickey Shuffle<\/a>. I’m not too bad with the Corgi Shuffle<\/a> though.\nI can do a pretty effective string shuffle. It is string shuffling that is required to make sense of the date string that is returned by WMI. This is because WMI dates are returned as strings<\/a> and not as datetime<\/b> objects. These strings are compliant with the Distributed Management Task Force (DMTF) Common Information Model (CIM) standards. In VBScript days, most scripters used a version of the function found in the Convert WMI Date-Time Values script<\/a> in the Scripting Guys Script Repository. EA, you are probably talking about this VBScript function in your email. It was a brilliant piece of code and is shown here:<\/p>\n

Function<\/span> <\/span>WMIDateStringToDate(dtmInstallDate)<\/span>
<\/span>WMIDateStringToDate<\/span> <\/span>=<\/span> <\/span>CDate(Mid(dtmInstallDate,<\/span> <\/span>5<\/span>,<\/span> <\/span>2<\/span>)<\/span> <\/span>&<\/span> “\/” <\/span>&<\/span> <\/span>_<\/span>
<\/span>Mid(dtmInstallDate,<\/span> <\/span>7<\/span>,<\/span> <\/span>2<\/span>)<\/span> <\/span>&<\/span> “\/” <\/span>&<\/span> <\/span>Left(dtmInstallDate,<\/span> <\/span>4<\/span>)<\/span> <\/span>_<\/span>
<\/span>&<\/span> ” ” <\/span>&<\/span> <\/span>Mid<\/span> <\/span>(dtmInstallDate,<\/span> <\/span>9<\/span>,<\/span> <\/span>2<\/span>)<\/span> <\/span>&<\/span> “:” <\/span>&<\/span> <\/span>_<\/span>
<\/span>Mid(dtmInstallDate,<\/span> <\/span>11<\/span>,<\/span> <\/span>2<\/span>)<\/span> <\/span>&<\/span> “:” <\/span>&<\/span> <\/span>Mid(dtmInstallDate,<\/span> <\/span>_<\/span>
<\/span>13<\/span>,<\/span> <\/span>2<\/span>))<\/span>
<\/span>End<\/span> <\/span>Function<\/span>\nInterestingly enough, in Windows XP<\/a> a new COM object was introduced to WMI—the SwbemDateTime object<\/a>. This object obsoleted the WMIDateStringToDate<\/b> function. This object is discussed in a Hey, Scripting Guy! TechNet Magazine<\/a> article called It’s About Time (Oh, and About Dates, Too)<\/a>. To use the SwbemDateTime<\/b> object, I wrote the FunDate<\/b> function, which is much easier to understand and is more reliable—and perhaps fun! <\/p>\n

Function<\/span> <\/span>funDate(wmiDate)<\/span>
<\/span>Dim<\/span> <\/span>objSWbemDateTime<\/span>
<\/span>Set<\/span> <\/span>objSWbemDateTime<\/span> <\/span>=<\/span> <\/span>CreateObject(<\/span>“WbemScripting.SWbemDateTime”<\/span>)<\/span>
<\/span>objSWbemDateTime.value<\/span> <\/span>=<\/span> <\/span>wmiDate<\/span>
<\/span>funDate<\/span> <\/span>=<\/span> <\/span>objSWbemDateTime.GetVarDate<\/span>
<\/span>End<\/span> <\/span>function<\/span>\nAn example of a WMI UTC date is seen here from the InstallDate<\/b> property of the Win32_OperatingSystem<\/b> WMI class. <\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span> <\/span>=<\/span> <\/span>Get-WmiObject<\/span> <\/span>win32_operatingsystem<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span>.InstallDate<\/span>
<\/span>20091024192037<\/span>.000000-240<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nEither of these approaches can be leveraged in Windows PowerShell<\/a>. To use the SwbemDateTime<\/b> object, use the New-Object<\/b> cmdlet to create an instance of the object. Use the Get-WmiObject<\/b> cmdlet to perform the WMI query of the Win32_OperatingSystem<\/b> class, supply the InstallDate<\/b> value to the value property of the SwbemDateTime<\/b> object, and call the GetVarDate<\/b> method from the same object. This technique is illustrated here:<\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>$swbem<\/span> <\/span>=<\/span> <\/span>New-Object<\/span> <\/span>-ComObject<\/span> <\/span>wbemscripting.swbemdatetime<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span> <\/span>=<\/span> <\/span>Get-WmiObject<\/span> <\/span>win32_operatingsystem<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$swbem<\/span>.Value<\/span> <\/span>=<\/span> <\/span>$os<\/span>.InstallDate<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$swbem<\/span>.GetVarDate()<\/span>
<\/span>Saturday,<\/span> <\/span>October<\/span> <\/span>24<\/span>,<\/span> <\/span>2009<\/span> <\/span>7<\/span>:<\/span>20<\/span>:<\/span>37<\/span> <\/span>PM<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nBut the System.Management.ManagementDateTimeConverter<\/a> .NET Framework class contains a number of static methods that are useful for working with WMI Dates. The static methods are shown here: <\/p>\n

PS C:> [management.managementDateTimeConverter] | gm -s<\/p>\n

   <\/span>TypeName: System.Management.ManagementDateTimeConverter<\/p>\n

Name               <\/span>MemberType Definition
—-               <\/span>———- ———-
Equals   <\/span>          <\/span>Method     <\/span>static bool Equals(System.Object objA, System.Objec…
ReferenceEquals    <\/span>Method     <\/span>static bool ReferenceEquals(System.Object objA, Sys…
ToDateTime         <\/span>Method     <\/span>static System.DateTime ToDateTime(string dmtfDate)
ToDmtfDateTime     <\/span>Method     <\/span>static string ToDmtfDateTime(System.DateTime date)
ToDmtfTimeInterval Method     <\/span>static string ToDmtfTimeInterval(System.TimeSpan ti…
ToTimeSpan         <\/span>Method     <\/span>static System.TimeSpan ToTimeSpan(string dmtfTimespan)<\/p>\n

PS C:><\/p>\n

<\/span><\/span>\nTo parse the InstallDate<\/b> property from the Win32_OperatingSystem<\/b> WMI class, you would use the ToDateTime<\/b> static method as illustrated here:<\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span> <\/span>=<\/span> <\/span>Get-WmiObject<\/span> <\/span>win32_operatingsystem<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>[management.managementDateTimeConverter]::ToDateTime(<\/span>$os<\/span>.InstallDate)<\/span>
<\/span>Saturday,<\/span> <\/span>October<\/span> <\/span>24<\/span>,<\/span> <\/span>2009<\/span> <\/span>7<\/span>:<\/span>20<\/span>:<\/span>37<\/span> <\/span>PM<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nThis can be accomplished in one line, by retrieving both the WMI class and selecting the property at the same time.\n\"Image\nThere is only one problem with using the management.managementDateTimeConverter<\/b> .NET Framework class—it is waaaaaaaaaaay toooooooooooo loooooong for me to type reliably on a regular basis. Therefore, this makes a great candidate to add to one’s profile<\/a>. Before I add anything to a profile, I like to test the command first to ensure it works. Here is the command and the “test”:<\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>New-Variable<\/span> <\/span>-Name<\/span> <\/span>dteConv<\/span> <\/span>-Value<\/span> <\/span>$<\/span>(<\/span>“management.managementDateTimeConverter”
<\/span>-as<\/span> <\/span>[<\/span>type<\/span>])<\/span> <\/span>-Description<\/span> <\/span>MrEd_Variable<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$dteConv<\/span>::ToDateTime((<\/span>gwmi<\/span> <\/span>win32_operatingSystem).InstallDate)<\/span>
<\/span>Saturday,<\/span> <\/span>October<\/span> <\/span>24<\/span>,<\/span> <\/span>2009<\/span> <\/span>7<\/span>:<\/span>20<\/span>:<\/span>37<\/span> <\/span>PM<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nI can edit a Windows PowerShell profile in Notepad, as shown in the following image. (Windows PowerShell profiles were discussed in Hey, Scripting Guy! Blog posts<\/a> during Profile Week.)\n\"?Image\nThere is another way to deal with WMI dates and times, and that is to use a ScriptMethod<\/b> that is added by the Windows PowerShell team to WMI objects. Two ScriptMethod<\/b>s are added, as shown via the Get-Member<\/b> cmdlet:<\/p>\n

PS C:> Get-WmiObject win32_OperatingSystem | Get-Member -MemberType ScriptMethod<\/p>\n

   <\/span>TypeName: System.Management.ManagementObject#rootcimv2Win32_OperatingSystem<\/p>\n

Name                <\/span>MemberType   <\/span>Definition
—-                <\/span>———-   <\/span>———-
ConvertFromDateTime ScriptMethod System.Object ConvertFromDateTime();
ConvertToDateTime   <\/span>ScriptMethod System.Object ConvertToDateTime();<\/p>\n

PS C:><\/p>\n

<\/span><\/span>\nBecause the ScriptMethod<\/b>s are added directly to instances of the WMI class, they can be accessed directly:<\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span> <\/span>=<\/span> <\/span>Get-WmiObject<\/span> <\/span>win32_OperatingSystem<\/span>
<\/span>PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span>.ConvertToDateTime(<\/span>$os<\/span>.InstallDate)<\/span>
<\/span>Saturday,<\/span> <\/span>October<\/span> <\/span>24<\/span>,<\/span> <\/span>2009<\/span> <\/span>7<\/span>:<\/span>20<\/span>:<\/span>37<\/span> <\/span>PM<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nUsing the ScriptMethod<\/b> always involves two steps: creating an instance of the WMI object, and passing an instance with the property to the ScriptMethod<\/b>. The only way to perform this on a single line is to use the semicolon to create two logical commands on a single physical line. This is shown here:<\/p>\n

PS<\/span> <\/span>C:><\/span> <\/span>$os<\/span> <\/span>=<\/span> <\/span>Get-WmiObject<\/span> <\/span>win32_OperatingSystem<\/span> <\/span>;<\/span> <\/span>$os<\/span>.ConvertToDateTime(<\/span>$os<\/span>.Install<\/span>
<\/span>Date)<\/span>
<\/span>Saturday,<\/span> <\/span>October<\/span> <\/span>24<\/span>,<\/span> <\/span>2009<\/span> <\/span>7<\/span>:<\/span>20<\/span>:<\/span>37<\/span> <\/span>PM<\/span>
<\/span>PS<\/span> <\/span>C:><\/span>\nThe advantage of always having access to the ConvertToDateTime<\/b> ScriptMethod<\/b> on an instance of a WMI class can be seen here. The gwmi<\/b> alias for the Get-WmiObject<\/b> cmdlet and the ft<\/b> alias for the Format-Table<\/b> cmdlet are used. A custom label is created for the table called “Installed”. The value of the installed date is created by using the ConvertToDateTime<\/b> ScriptMethod<\/b>. The results can be compared to creating a table with the version and the installdate<\/b> without parsing the date:<\/p>\n

PS C:> gwmi win32_operatingsystem | ft version, @{LABEL=”Installed”; EXPRESSION = {$
_.convertToDateTime($_.InstallDate)}}<\/p>\n

version                                    <\/span>Installed
——-                                    <\/span>———
6.1.7600                                   <\/span>10\/24\/2009 7:20:37 PM<\/p>\n

PS C:> gwmi win32_operatingsystem | ft version, installDate<\/p>\n

version                                    <\/span>installDate
——-                                    <\/span>———–
6.1.7600                                   <\/span>20091024192037.000000-240<\/p>\n

PS C:><\/span>\n
<\/span>EA, that is all there is to using dates when working with Windows Management Instrumentation (WMI). That also brings Date Week to a close. Join us tomorrow for Quick-Hits Friday<\/a>.\nWe invite you to follow us on Twitter<\/a> or Facebook<\/a>. If you have any questions, send email to us at scripter@microsoft.com<\/a>, or post your questions on the Official Scripting Guys Forum<\/a>. See you tomorrow. Until then, peace.\n \nEd Wilson and Craig Liebendorfer, Scripting Guys<\/b>\n<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

  Hey, Scripting Guy! I need to understand how to work with dates that I receive from Windows Management Instrumentation (WMI). I remember in VBScript I had to use a function I got from the Scripting Guys that did string manipulation to convert the WMI date to a “normal” date. I guess that is okay, […]<\/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-17531","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":"

  Hey, Scripting Guy! I need to understand how to work with dates that I receive from Windows Management Instrumentation (WMI). I remember in VBScript I had to use a function I got from the Scripting Guys that did string manipulation to convert the WMI date to a “normal” date. I guess that is okay, […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/17531","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/users\/595"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/comments?post=17531"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/17531\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media\/87096"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media?parent=17531"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/categories?post=17531"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/tags?post=17531"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}