Get the last recorded login timestamp for users across multiple domain controllers

Get-ADUserLastLogon.ps1

#Requires -Module ActiveDirectory

using namespace Microsoft.ActiveDirectory.Management;

function Get-ADUserLastLogon
{
    <#
    .SYNOPSIS
        Get the last recorded login for one or more users across one or more domain controllers

    .EXAMPLE
        PS C:\> $LoginRecords = Get-ADUser -Filter '*' | Get-ADUserLastLogon;
        PS C:\> $LoginRecords;

        Get a list of users, and then return the last login recorded
        across all domain controllers for those users

    .EXAMPLE
        PS C:\> $LoginRecords = Get-ADUser -Filter '*' |
        >>        Get-ADUserLastLogon -DomainControllers (Get-ADDomainController -Filter { Name -like 'DC1' });

        PS C:\> $LoginRecords;

        Get a list of users, and then return the last login recorded
        across a filtered list of domain controllers for those users

    .INPUTS
        Microsoft.ActiveDirectory.Management.ADUser
        Microsoft.ActiveDirectory.Management.ADDomainController[]

    .OUTPUTS
        System.Collections.Hashtable[]
    #>

    [CmdletBinding()]
    [OutputType([HashTable])]

    param (
        [Parameter(Mandatory, ValueFromPipeline)]
        [ADUser] $User,

        [Parameter()]
        [ADDomainController[]] $DomainControllers = (Get-ADDomainController -Filter { Name -like '*' })
    );

    process
    {
        $LastLogin = [DateTime]::Parse('12/31/1600');

        foreach ($DomainController in $DomainControllers)
        {
            $UserOnDomainController = Get-ADUser $User.SamAccountName |
                Get-ADObject -Server $DomainController.HostName -Properties 'lastLogon'

            $LastLoginOnDomainController = [DateTime]::FromFileTime($UserOnDomainController.LastLogon);

            if ($LastLoginOnDomainController -gt $LastLogin)
            {
                $LastLogin = $LastLoginOnDomainController;
            }
        }

        if ($LastLogin -le [DateTime]::Parse('12/31/1601'))
        {
            $LastLogin = $null;
        }

        return @{
            User = $User;
            LastLogin = $LastLogin;
        };
    }
}