D:> Get-ADComputer adil-7600-8 -Properties pwdlastset pwdlastset : 130575614253222449
The other property, PasswordLastSet is as helpful as it gets:
D:> Get-ADComputer adil-7600-8 -Properties passwordlastset PasswordLastSet : 10/12/2014 12:23:45 AM
Why? Well, I am not sure why Microsoft decided to provide two different properties for this value, probably pwdLastSet is easier for calculations. That is probably why the type of pwdLastSet is signed 64 bit integer (int64) vs. DateTime for PasswordLastSet
D:> Get-ADComputer adil-7600-8 -properties pwdlastset |get-member pwdlastset TypeName: Microsoft.ActiveDirectory.Management.ADComputer Name MemberType Definition ---- ---------- ---------- pwdlastset Property System.Int64 pwdlastset {get;set;} D:> Get-ADComputer adil-7600-8 -properties passwordlastset |get-member passwordlastset TypeName: Microsoft.ActiveDirectory.Management.ADComputer Name MemberType Definition ---- ---------- ---------- PasswordLastSet Property System.DateTime PasswordLastSet {get;set;}