Yes. In the contrary to Supersaver Tickets, Saver Day Passes and regular point-to-point tickets are valid on any train connection.
Our rail network is mass transit similar to metro trains; meaning, you show up at the station, you check the platform from where your train will leave, you get on the train after its arrival, and you take a free seat in the respective seating class.
As a sign of respect, if you wish to take a seat next to a fellow passenger, it is common practice to ask if the seat next to the person is free - even though it obviously is. You will get a smile back as confirmation.
Buy what ever is less costly, the Saver Day Pass or the point-to-point ticket. Saver Day Passes are available online 60 days out.
Let us know should you have more queries.