Types/UserProfileTypes.ps1xml

<Types>
    <Type>
        <Name>UserProfile</Name>

        <!-- Adding a calculated property to check if the profile is inactive -->
        <Members>
            <MemberSet>
                <Name>PSStandardMembers</Name>
                <Members>
                    <PropertySet>
                        <Name>DefaultDisplayPropertySet</Name>
                        <ReferencedProperties>
                            <Name>SID</Name>
                            <Name>UserName</Name>
                            <Name>ProfilePath</Name>
                            <Name>IsOrphaned</Name>
                            <Name>OrphanReason</Name>
                            <Name>ComputerName</Name>
                            <Name>LastLogonDate</Name>
                        </ReferencedProperties>
                    </PropertySet>
                </Members>
            </MemberSet>
            <ScriptProperty>
                <Name>IsInactive</Name>
                <GetScriptBlock>
                    if ($this.LastLogonDate -eq [datetime]::MinValue) {
                    $false
                    } elseif ($this.LastLogonDate -lt (Get-Date).AddMonths(-6)) {
                    $true
                    } else {
                    $false
                    }
                </GetScriptBlock>
            </ScriptProperty>

            <!-- Add a custom property that displays LastLogonDate as null if it's 1/1/0001 12:00:00
            AM -->
            <ScriptProperty>
                <Name>FormattedLastLogonDate</Name>
                <GetScriptBlock>
                    if ($this.LastLogonDate -eq [datetime]::MinValue) {
                    $null
                    } else {
                    $this.LastLogonDate
                    }
                </GetScriptBlock>
            </ScriptProperty>

            <!-- Add a method to the UserProfile class -->
            <ScriptMethod>
                <Name>GetProfileSummary</Name>
                <Script>
                    return "Profile for $($this.UserName): Last Logon
                    $($this.FormattedLastLogonDate)"
                </Script>
            </ScriptMethod>

        </Members>
    </Type>
</Types>