A statute is effective on the date that it takes effect, unless it indicates that it is retrospective. “‘A statute is not operative as law until the date at which it takes effect[.] and it operates prospectively unless the intent that it operate retrospectively is clearly expressed.” Imperial Point Colonnades Condo., Inc. v. Freedom Props. Int’l, Inc., 349 So.2d 1194, 1195 (Fla. 4th DCA 1977) (citations omitted); see also Horn v. Florida Dep’t of Revenue ex rel. Abel, 752 So. 2d 687, 688 (Fla. 3d DCA 2000) (” ‘This rule applies with particular force to those instances where retrospec¬tive operation of the law would impair or destroy existing rights.’ ” (quoting State v. Lavazzoli, 434 So. 2d 321, 323 (Fla. 1983))). [T]he court’s retroactive application of these amendments to remove the former wife’s designation as the “primary residential parent” and establish 50/50 time-sharing between the parties clearly impaired the former wife’s existing rights over her children. See Horn, 752 So. 2d at 688. The inclusion of the October 1, 2008, effective date for the amendments also rebuts any argument that retroactive application of section 61.13, as amended, was intended by the Legislature. See State Dep’t of Revenue v. Zuckerman-Vernon Corp., 354 So. 2d 353, 358 (Fla. 1977); see also Imperial Point Colonnades Condo., Inc., 349 So. 2d at 1195; Poole v. Savage, 561 So. 2d 360, 363 (Fla. 1st DCA 1990).” Hahn v. Hahn