The analysis also revealed Prince Charles held third place with 160 days, while Prince Andrew took part in 140 days, the Duke of Cambridge participated in 120 engagements and Prince Harry worked for just over 90.
Kate Middleton and Meghan Markle hit the bottom of the list, with their total recorded working days at 100.
Princess Anne also came in first in 2017 with a whopping 455 official appearances and 85 engagements overseas.