The code here will get the list of all management packs updated in the last 24 hours. We can change this interval by changing the hours (24 in this example) in the following code to get the list of the management packs updated in the custom intervals:

$MyDate = (Get-Date).AddHours(-24)
$AllMPs = Get-SCOMManagementPack
$ModifiedMPs= $AllMPs | Where {$_.LastModified -gt $MyDate} 
  | Select-Object Name, LastModified | Sort LastModified 
$ModifiedMPs | Out-File –FilePath "C:\SCOM\MP\updated.txt"