WMI Date Formats … PowerShell to the Rescue

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If you use WMI in your PowerShell scripts you’ll probably have noticed that dates are shown in a rather odd format.  For example:

Get-WmiObject –Class Win32_BIOS |
     Format-Table Description, ReleaseDate -AutoSize

Description          ReleaseDate             
-----------          -----------             
Phoenix ROM BIOS A14 20090511000000.000000+000

While you can read the dates (they are in “year-month-day-hour-minute-second” format), they are difficult to parse quickly, especially if you have a long table filled with them.

Fortunately, PowerShell helps you out by adding the ConvertToDateTime() method to each WMI object.  This allows you to do things like this:

$os = Get-WmiObject –Class Win32_OperatingSystem
$os.ConvertToDateTime($os.InstallDate)

10 May 2011 14:54:26

It is easy to include this in a table using a calculated property:

$Lease = @{Label=“Lease Expires”;  
Expression={$_.ConvertToDateTime($_.DHCPLeaseExpires)}}

Get-WmiObject -Class Win32_NetworkAdapterConfiguration `
    -Filter "NOT DHCPLeaseExpires = NULL" |
         Format-Table Description, $Lease –Autosize

Description                 Lease Expires      
-----------                 ------------      
Intel(R) WiFi Link 5300 AGN 04/08/2011 18:49:09

Strictly speaking the hashtable could be defined in-line with the Format-Table cmdlet, but I’ve put it on its own line for readability.