Check for expired passwords

How can I check if an Active Directory password is already expired? It is useful for one own password but also to check if password expiration is the reason why a certain user cannot login.

I found this PowerShell script in one of my PowerShell profiles (PS: I did not create it. I think i got it from here http://blogs.msdn.com/b/adpowershell/archive/2010/02/26/find-out-when-your-password-expires.aspx).

Here is the script:

new-alias -name Get-PWExp -value "Get-XADUserPasswordExpirationDate"


function Get-XADUserPasswordExpirationDate() {
Param ([Parameter(Mandatory=$true,  Position=0,  ValueFromPipeline=$true, HelpMessage="Identity of the Account")]
[Object] $accountIdentity)
PROCESS {
$accountObj = Get-ADUser $accountIdentity -properties PasswordExpired, PasswordNeverExpires, PasswordLastSet
if ($accountObj.PasswordExpired) {
echo ("Password of account: " + $accountObj.Name + " already expired!")
} else { 
if ($accountObj.PasswordNeverExpires) {
echo ("Password of account: " + $accountObj.Name + " is set to never expires!")
} else {
$passwordSetDate = $accountObj.PasswordLastSet
if ($passwordSetDate -eq $null) {
echo ("Password of account: " + $accountObj.Name + " has never been set!")
}  else {
$maxPasswordAgeTimeSpan = $null
$dfl = (get-addomain).DomainMode
if ($dfl -ge 3) { 
## Greater than Windows2008 domain functional level
$accountFGPP = Get-ADUserResultantPasswordPolicy $accountObj
if ($accountFGPP -ne $null) {
$maxPasswordAgeTimeSpan = $accountFGPP.MaxPasswordAge
} else {
$maxPasswordAgeTimeSpan = (Get-ADDefaultDomainPasswordPolicy).MaxPasswordAge
}
} else {
$maxPasswordAgeTimeSpan = (Get-ADDefaultDomainPasswordPolicy).MaxPasswordAge
}
if ($maxPasswordAgeTimeSpan -eq $null -or $maxPasswordAgeTimeSpan.TotalMilliseconds -eq 0) {
echo ("MaxPasswordAge is not set for the domain or is set to zero!")
} else {
echo ("Password of account: " + $accountObj.Name + " expires on: " + ($passwordSetDate + $maxPasswordAgeTimeSpan))
}
}
}
}
}
}