Which of the US time zones is largest in area?

Central Time Zone, the largest one by area, encompasses 20 states, but only 10 of them are located entirely within zone's boundaries, all remaining states have some exceptions.

https://www.countries-ofthe-world.com/time-zones-usa.html#:~:text=UTC%2D06%3A00%20Central%20Time,remaining%20states%20have%20some%20exceptions.

The largest time zone in the United States by area is the Central time zone (UTC -6.00), which encompasses a total of 20 states, although only ten are wholly covered by Central time. Of the remaining ten, five (Florida, Indiana, Kentucky, Michigan and Tennessee) are split between the Central and Eastern time zones, and five (Kansas, Nebraska, North Dakota, South Dakota and Texas) are split between Central and Mountain time. Additionally, areas of Nunavut and Ontario, and most of Saskatchewan in Canada, 3/4 of the territory of Mexico, and six countries in Central America are also within the Central time zone.

https://en.wikipedia.org/wiki/Central_Time_Zone