Iowa Code § 1C.4: Independence Sunday.

The governor is hereby authorized and requested to issue annually a proclamation, calling upon the citizens of Iowa to assemble themselves in their respective communities for the purpose of holding suitable religious-patriotic services and the display of the American colors, in commemoration of the signing of the Declaration of Independence, on Independence Sunday, which is hereby established as the Sunday preceding the Fourth of July of each year, or on the Fourth when that date falls on Sunday.