Powershell Datetime null value - powershell

Question

I am developing a powershell about the AD user account expire date. But I have occurred a problem which is unable to pass the empty parameter to set the AD user account expire date to NEVER.
Please help! Thanks.
https://i.stack.imgur.com/Zt8sv.png
Here are my script below.
import-module C:\PS\color_menu.psm1
CreateMenu -Title "AD User Account Expire Tools" -MenuItems "View the User Account Expire Date","Set the User Account Expire Date","Exit" -TitleColor Red -LineColor Cyan -menuItemColor Yellow
do {
[int]$userMenuChoice = 0
while ( $userMenuChoice -lt 1 -or $userMenuChoice -gt 3) {
Write-Host "1. View the User Account Expire Date"
Write-Host "2. Set the User Account Expire Date"
Write-Host "3. Exit"
[int]$userMenuChoice = Read-Host "Please choose an option"
switch ($userMenuChoice) {
1{$useraccount = Read-Host -prompt "Please input an user account"
Get-ADUser -Identity $useraccount -Properties AccountExpirationDate | Select-Object -Property SamAccountName, Name, AccountExpirationDate
Write-Host "";
Write-Host "";
}
2{$useraccount = Read-Host -prompt "Please input an user account"
[Datetime]$expiredatetime = Read-Host -prompt "Please input the user expire date and time (DateFormat: MM/dd/yyyy)"
Set-ADAccountExpiration -Identity $useraccount -DateTime $expiredatetime
Write-Host "";
Write-Host "";
Get-ADUser -Identity $useraccount -Properties AccountExpirationDate | Select-Object -Property SamAccountName, Name, AccountExpirationDate
Write-Host "";
Write-Host "";
}
3{Write-Host "Exit";Exit
}
default {Write-Host "Incorrect input" -ForegroundColor Red
Write-Host "";
Write-Host "";
}
}
}
} while ( $userMenuChoice -ne 3 )```

Answer 1

Use Clear-ADAccountExpiration to set an account to never expire.
Also, you cannot directly use a [datetime] type-constrained variable with your Read-Host call, because converting the empty string ('') to [datetime] isn't supported (the error you saw).
Here's one way to solve this:
do {
# Read the input as a string first...
$expiredatetimeStr = Read-Host -prompt "Please input the user expiration date and time (DateFormat: MM/dd/yyyy) or just press Enter to make the account non-expiring"
# ... and then try to convert it to [datetime]
if ($expiredatetime = $expiredatetimeStr -as [datetime]) {
Set-ADAccountExpiration -Identity $useraccount -DateTime $expiredatetime
}
elseif ($expiredatetimeStr.Trim() -eq '') { # empty input -> no expiration
Clear-ADAccountExpiration -Identity $useraccount
}
else { # invalid input
Write-Warning 'Please enter a valid date.'
continue
}
break
} while ($true)