Mr Bates takes part in gundog trialling, taking his dog Mable to Hannahs Bay every morning to keep it fit.
"That keeps me very active."
Mr Bates is also a patron of the Rotorua Tramping and Skiing Club.
Mrs Bates said she had been involved in embroidery for more than 30 years and was very involved in making curtains for the home of George Washington's ancestors, Sulgrave Manor, as well as the Rotorua Public Library's wall hanging.
She was also the national president of the Embroiderers Guild for four years.
She said they had also travelled both overseas and around New Zealand a lot.
"We loved England and Canada, Tasmania we enjoyed too, and we had a lot of fun in Europe."
Mrs Bates said common interests they had were gardening, having an active life in St Luke's Church and hospitality.
"We love having people for meals."
She said a tip for a long and healthy relationship was to share what they were doing and take an interest in each other's hobbies.
To celebrate their diamond anniversary they will be having a luncheon with family and close friends on Saturday, Mrs Bates said.
"Everyone says they are coming with bells on."
They have also received cards from the Queen, Prime Minister, Minister of Internal Affairs and a letter from Labour leader Andrew Little to congratulate them.