Please explain fully

Having read and understood the Kerberos scheme, consider the following variant of Kerberos. Instead of having postdated or renewable tickets (2 types of tickets), a server, which notes that the start-time is older than some limit, presents the ticket to the TGS and asks if it should believe the ticket. What are the trade-offs of this approach to the Kerberos V5 approach? (You will need to understand the Kerberos V process to answer this.)