"Who was that Marvellous Fluorescent-Vested Highway-Dancing Hero?" she wondered.
The video was posted earlier this month and has been shared more than 300 times since Hatherly made it public, after a friend suggested she spread the joy more widely.
"It was so wonderful and uplifting to witness," she told the Herald.
Hatherly says she's tried to find the man's identity but, so far, hasn't been successful. She wanted to let him know the joy he'd brought to her day.
"He can't see the expressions of people passing by. Everyone was so happy, I'd love for him to know that," she added.
"It's the spirit of New Zealand."