Powershell giving wrong output after scheduling with window's task scheduler - windows

Question

I have a PowerShell script to check the password expiry date of the a system user and send a mail if it is going to expire within 10 days. Script works fine when we run it stand alone. But it show abnormal behaviour after scheduling it with windows task scheduler. Sometimes it works perfectly fine and sometimes it's not.
Output: Password will Expire in -736235 Days.
Expected output: Password will Expire in Days.
It always give -736235 days when if runs incorrectly.
Here is the configuration,
1.General tab
- Run whether user logged in or not
- Run with highest Privilege
- Configure for : Windows server 2012 R2
Action Tab
Program/script: PowerShell
-Add Argument: .\ps.ps1
Start in: D:
Setting Tab(Following Options are checked)
-Allow task to run on demand
Stop task if it running from: 3 days
-if the running task doesn't stop when requested, force stop
If the task is already running then following rule will apply: Stop the existing instance.
Please let me know if you need any other details,
Thanks,
Navdeep
Script is,
$user = Get-ADUser -filter {Enabled -eq $True -and PasswordNeverExpires -eq $False -and Name -eq "<user_name>" } –Properties "DisplayName", "msDS-UserPasswordExpiryTimeComputed" | Select-Object -Property "Displayname",#{Name="ExpiryDate";Expression={[datetime]::FromFileTime($_."msDS-UserPasswordExpiryTimeComputed")}}
$DayCount = $user.ExpiryDate - (GET-DATE)
$DayAbsCount = $DayCount.Days
$message.body = "Password will Expire in $DayAbsCount Days.Please reset."
if ( $DayAbsCount -lt 10)
{
$smtp = new-object Net.Mail.SmtpClient($smtpserver)
$smtp.Send($message)
}
,
and the script is running from the same account whose pwd expiration date we needed.