diff --git a/src/core_modules/capture-core/utils/converters/date/convertStringToTemporal.js b/src/core_modules/capture-core/utils/converters/date/convertStringToTemporal.js
index 5eee8cc7a1..a50c92be11 100644
--- a/src/core_modules/capture-core/utils/converters/date/convertStringToTemporal.js
+++ b/src/core_modules/capture-core/utils/converters/date/convertStringToTemporal.js
@@ -9,7 +9,13 @@ import { systemSettingsStore } from '../../../metaDataMemoryStores';
  * @returns {(Temporal.PlainDate | null)}
  */
 
-export function convertStringToTemporal(dateString: string): Temporal.PlainDate | null {
+type PlainDate = {
+    year: number,
+    month: number,
+    day: number
+};
+
+export function convertStringToTemporal(dateString: ?string): PlainDate | null {
     if (!dateString) {
         return null;
     }
@@ -34,6 +40,6 @@ export function convertStringToTemporal(dateString: string): Temporal.PlainDate
             calendar,
         });
     } catch (error) {
-        return '';
+        return null;
     }
 }
diff --git a/src/core_modules/capture-core/utils/converters/date/convertTemporalToString.js b/src/core_modules/capture-core/utils/converters/date/convertTemporalToString.js
index a295b7984d..e413468c66 100644
--- a/src/core_modules/capture-core/utils/converters/date/convertTemporalToString.js
+++ b/src/core_modules/capture-core/utils/converters/date/convertTemporalToString.js
@@ -1,5 +1,4 @@
 // @flow
-import { Temporal } from '@js-temporal/polyfill';
 import { padWithZeros } from './padWithZeros';
 import { systemSettingsStore } from '../../../../capture-core/metaDataMemoryStores';
 
@@ -9,7 +8,13 @@ import { systemSettingsStore } from '../../../../capture-core/metaDataMemoryStor
  * @returns {string} Formatted date string, or empty string if invalid
  */
 
-export function convertTemporalToString(temporalDate: Temporal.PlainDate | null): string {
+type PlainDate = {
+    year: number,
+    month: number,
+    day: number
+};
+
+export function convertTemporalToString(temporalDate: PlainDate | null): string {
     if (!temporalDate) {
         return '';
     }
diff --git a/src/core_modules/capture-ui/AgeField/AgeField.component.js b/src/core_modules/capture-ui/AgeField/AgeField.component.js
index b04b755613..fccf96d0e9 100644
--- a/src/core_modules/capture-ui/AgeField/AgeField.component.js
+++ b/src/core_modules/capture-ui/AgeField/AgeField.component.js
@@ -28,10 +28,6 @@ type InputMessageClasses = {
     validating?: ?string,
 }
 
-type DateParser = (value: string) => { isValid: boolean, momentDate: any };
-
-type DateStringFromMomentFormatter = (momentValue: Object) => string;
-
 type ValidationOptions = {
     error?: ?string,
     errorCode?: ?string,