How to convert a string value to date

Question

Dear All,
I am new to powershell script, i was trying to store a Ad user password set date to a variable add, add a number of days to get the expire date.
but when i try to convert the variable to date value, I am getting the error as below.
Please help me......
PS C:\script> $passwordSetDate = (get-aduser user1 -properties * | select PasswordLastSet)
PS C:\script> $passwordSetDate
PasswordLastSet
7/15/2014 8:17:24 PM
PS C:\script> $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)
Cannot find an overload for "ParseExact" and the argument count: "3".
At line:1 char:1
+ $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodCountCouldNotFindBest
PS C:\script> $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)

Answer 1

Dear All,
I am new to powershell script, i was trying to store a Ad user password set date to a variable add, add a number of days to get the expire date.
but when i try to convert the variable to date value, I am getting the error as below.
Please help me......
PS C:\script> $passwordSetDate = (get-aduser user1 -properties * | select PasswordLastSet)
PS C:\script> $passwordSetDate
PasswordLastSet
7/15/2014 8:17:24 PM
PS C:\script> $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)
Cannot find an overload for "ParseExact" and the argument count: "3".
At line:1 char:1
+ $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodCountCouldNotFindBest
PS C:\script> $a = [datetime]::ParseExact($passwordSetDate,"MM/dd/yyyy HH:MM:SS", $null)
In your post you ask how to convert a string value to a date.  The value returned from the Get-AdUser is already a date.  It does not need to be converted.
Bill has sshown one way to convert a date to a string and there are other methods.  You need to clarify your question.
If you are really trying ot convert strings to dates then you can start with this:
[datetime]'01/21/1965 13:33:23'
Most date strings aer autodetected by the class.
¯\_(ツ)_/¯