Get-WmiObject win32_ntlogevent -filter "logfile='system' AND EventCode=6005 AND TimeWritten > '$((get-date).AddDays(-30).toShortDateString())'" -computername (get-content computers.txt) |Select @{name="Computername";Expression={$_.__Server}},@{name="StartUp";Expression={$_.ConvertToDateTime($_.timewritten)}}