Select-Object -Property `
    Id,
    @{
        Name       = 'Test'
        Expression = {
            # To avoid errors (as we check for them later in the script), only
            # parse the string if it's a non-empty.
            if (![String]::IsNullOrEmpty($_.Expires)) {
                [DateTime]::ParseExact($_.Expires, $dateFormat, $null)
            }
        }
    }