definition of “Whole numbers” is also ambiguous like Natural numbers.
As you said some authors include 0 in the set of natural numbers and some don’t.
Likewise, some authors use set $\{0,1,2,3,...\}$ as set of whole numbers and some authors use $\{1,2,3,...\}$ while some authors use $\{…,-3,-2,-1,0,1,2,3,...\}$ as the set of whole numbers.