Pokémon Sword and Pokémon Shield are 2019 role-playing video games developed by Game Freak and published by The Pokémon Company and Nintendo for the Nintendo Switch. They are the first installments in the eighth generation of the Pokémon video game series and the second in the series, following Pokémon: Let’s Go, Pikachu! and Let’s Go, Eevee!, released on a home game console. Pokémon Sword and Shield were released in November 2019. https://en.wikipedia.org/wiki/Pok%C3%A9mon_Sword_and_Shield
According to SegmentNext it takes a maximum of 3 to 4 minutes for any egg to hatch. https://segmentnext.com/2019/11/20/how-to-hatch-eggs-fast-in-pokemon-sword-and-shield/
An alternative method, should you will to use it, is to go to the Route 5 Nursery, and simply go up and down until the egg hatches. You can boost the speed of this process up by collecting Watts in the Wild Area and simply interacting with the Watt Trader. You should then have the ability to do the turbo more often. The ability may cost a lot of Watts so you might want to save up on this. Having the additional speed will definitely speed up the hatching process even more.