For passes issued by other County Councils there was a concessionary rate available at all times of the day/week. Buy a ticket at machine but do make sure that you carry your pass!
'Pass holders from other council areas need to purchase a concession return tram ticket from the tram stop ticket machines'
The rate for a Concession day ticket is £3.
The NET website refers to this as a "concession return tram ticket", which would suggest that it is only valid for one out and back journey on the tram, but if you click on Tickets and then on Day Tickets, it has the £3 concessionary ticket listed, which would suggest that it is an all-day ticket valid for unlimited travel on the day of issue.
It also says it is available to UK concessionary pass holders from outside Nottinghamshire, which would suggest that it is also available to concessionary pass holders from Scotland, Wales and Northern Ireland (who do not generally qualify for free or concessionary travel outside their own country of the UK).
As an aside, I notice that the NET website says you can buy tickets from the NET Travel Centre at 4 King Street, Nottingham but it doesn't say what types of tickets can be bought there. Does anyone know what types of tickets are sold there?