add card util function

Author: carlosmiceli

src/libs/CardUtils.ts

@@ -1,5 +1,5 @@
 import type {FeedKeysWithAssignedCards} from '@selectors/Card';
-import {fromUnixTime, isBefore} from 'date-fns';
+import {format, fromUnixTime, isBefore} from 'date-fns';
 import groupBy from 'lodash/groupBy';
 import type {OnyxCollection, OnyxEntry} from 'react-native-onyx';
 import type {TupleToUnion, ValueOf} from 'type-fest';
@@ -840,6 +840,22 @@ function getDefaultCardName(cardholder?: string) {
     return `${cardholder}'s card`;
 }
 
+/**
+ * Gets the start date for a card assignment.
+ * When not editing, always returns the current date.
+ * When editing, returns the existing start date or current date as fallback.
+ *
+ * @param isEditing - Whether the card assignment is being edited
+ * @param existingStartDate - The existing start date from previous assignment
+ * @returns Formatted start date string in yyyy-MM-dd format
+ */
+function getCardAssignmentStartDate(isEditing: boolean | undefined, existingStartDate?: string): string {
+    if (!isEditing) {
+        return format(new Date(), CONST.DATE.FNS_FORMAT_STRING);
+    }
+    return existingStartDate ?? format(new Date(), CONST.DATE.FNS_FORMAT_STRING);
+}
+
 function checkIfNewFeedConnected(prevFeedsData: CompanyFeeds, currentFeedsData: CompanyFeeds, plaidBank?: string) {
     const prevFeeds = Object.keys(prevFeedsData);
     const currentFeeds = Object.keys(currentFeedsData);
@@ -1196,6 +1212,7 @@ export {
     hasOnlyOneCardToAssign,
     checkIfNewFeedConnected,
     getDefaultCardName,
+    getCardAssignmentStartDate,
     getDomainOrWorkspaceAccountID,
     mergeCardListWithWorkspaceFeeds,
     isCard,