Exchange 2010 SP3 - Litigation hold duration

Hi All

Hope everyone is good.

I had a question that I cannot seem to find an answer to on the WWW. In Exchange 2010 when you turn on litigation hold for a mailbox you cannot define a duration. I cannot seem to find these settings anywhere. Any ideas?

[PS] C:\Windows\system32>Get-Mailbox navzonprem | Select *litig* | fl

LitigationHoldEnabled : True
LitigationHoldDate : 11/22/2018 2:16:31 PM
LitigationHoldOwner : Admin Navishkar

[PS] C:\Windows\system32>set-Mailbox navzonprem -LitigationHoldEnabled $true -LitigationHoldDuration 365
A parameter cannot be found that matches parameter name 'LitigationHoldDuration'.
+ CategoryInfo : InvalidArgument: (:) [Set-Mailbox], ParameterBindingException
+ FullyQualifiedErrorId : NamedParameterNotFound,Set-Mailbox
+ PSComputerName : exserver