LocalHost converting the LastBoot time of RemoteHost into LocalTime

The Uptime script showing correct LastBoot time on local server however showing incorrect LastBoot time of Remote server. LocalHost converting the LastBoot time or RemoteHost into LocalTime

Function get-Uptime {
Param([string]$computername=$env:computername)
Process{
if ($_) {$computername=$_}
    $Computerobj = "" | select ComputerName, Uptime, LastReboot, TimeZone
    $WOS = Get-WmiObject -Class Win32_OperatingSystem -ComputerName $ComputerName
    $LastBootUpTime = $WOS.ConvertToDateTime($WOS.LastBootUpTime)
    $Uptime = (Get-Date) - $LastBootUpTime
    $day =$Uptime.Days
    $hour =$Uptime.Hours
    $minute =$Uptime.Minutes
    $second = $Uptime.Seconds
    $timz = Get-WmiObject -Class win32_timezone -ComputerName $computername |Select -ExpandProperty Caption
$Computerobj.ComputerName = $computername
$Computerobj.Uptime = "$day Days $hour Hours $minute Min $second Sec"
$Computerobj.LastReboot = $LastBootUpTime
$Computerobj.TimeZone = $timz
$Computerobj    
}
}


*****LocalHost****** LastReboot Correctly displayed***
ComputerName : LocalHost
Uptime       : 72 Days 12 Hours 56 Min 14 Sec
LastReboot   : 1/29/2014 3:18:46 AM
TimeZone     : (UTC-05:00) Eastern Time (US & Canada)

*****RemoteHost****** LastReboot incorrecly displayed***
ComputerName : RemoteHost
Uptime       : 73 Days 12 Hours 47 Min 52 Sec
LastReboot   : 1/28/2014 3:27:55 AM
TimeZone     : (UTC-08:00) Pacific Time (US & Canada)

*****Actual LastReboot time on RemoteHost******

ComputerName : RemoteHost
Uptime       : 73 Days 12 Hours 47 Min 52 Sec
LastReboot   : 1/28/2014 12:27:55 AM
TimeZone     : (UTC-08:00) Pacific Time (US & Canada)