fix: SSR hydration mismatch from Date.now private prop keys (adobe#9787)

Author: reidbarber

packages/@react-aria/datepicker/src/useDateField.ts

@@ -55,8 +55,9 @@ export const hookData: WeakMap<DateFieldState, HookData> = new WeakMap<DateField
 
 // Private props that we pass from useDatePicker/useDateRangePicker.
 // Ideally we'd use a Symbol for this, but React doesn't support them: https://github.com/facebook/react/issues/7552
-export const roleSymbol: string = '__role_' + Date.now();
-export const focusManagerSymbol: string = '__focusManager_' + Date.now();
+// These need to be stable across server and client module evaluation for SSR hydration.
+export const roleSymbol: string = '__reactAriaDateFieldRole';
+export const focusManagerSymbol: string = '__reactAriaDateFieldFocusManager';
 
 /**
  * Provides the behavior and accessibility implementation for a date field component.

packages/@react-stately/form/src/useFormValidationState.ts

@@ -41,7 +41,10 @@ export const DEFAULT_VALIDATION_RESULT: ValidationResult = {
 
 export const FormValidationContext: Context<ValidationErrors> = createContext<ValidationErrors>({});
 
-export const privateValidationStateProp: string = '__formValidationState' + Date.now();
+// Private props that we pass from useFormValidationState to children.
+// Ideally we'd use a Symbol for this, but React doesn't support them: https://github.com/facebook/react/issues/7552
+// This needs to be stable across server and client module evaluation for SSR hydration.
+export const privateValidationStateProp: string = '__reactAriaFormValidationState';
 
 interface FormValidationProps<T> extends Validation<T> {
   builtinValidation?: ValidationResult,