Get-HotFix and get-WmiObject Win32_QuickFixEngineering missing InstalledOn property

Hello All

When using either of the above,  most of my HotFixes show no InstalledOn or InstalledDate

However when I look in Control Panel > Programs and Features > View Installed Updates

they all show an Installed On date

I want to collect this information from local/remote computers and will therefore use the WMI option in my environment, but I need to retrieve the InstalledOn

If the above has a bug perhaps I need to go looking around in the registry,

any help most appreciated

Thanks

Ernie