From fd8722e40144a7010d6f52a73de06cd17a779df7 Mon Sep 17 00:00:00 2001
From: James Cole <james@firefly-iii.org>
Date: Fri, 1 May 2026 13:46:57 +0200
Subject: [PATCH] Fix https://github.com/orgs/firefly-iii/discussions/12210

---
 app/Repositories/PiggyBank/ModifiesPiggyBanks.php       | 4 ++--
 app/Support/JsonApi/Enrichments/PiggyBankEnrichment.php | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/app/Repositories/PiggyBank/ModifiesPiggyBanks.php b/app/Repositories/PiggyBank/ModifiesPiggyBanks.php
index 92695f652e..43852665f2 100644
--- a/app/Repositories/PiggyBank/ModifiesPiggyBanks.php
+++ b/app/Repositories/PiggyBank/ModifiesPiggyBanks.php
@@ -385,9 +385,9 @@ trait ModifiesPiggyBanks
             $piggyBank->target_date    = $data['target_date'];
             $piggyBank->target_date_tz = $data['target_date']?->format('e');
         }
-        if (array_key_exists('start_date', $data)) {
+        if (array_key_exists('start_date', $data) && '' !== $data['start_date']) {
             $piggyBank->start_date    = $data['start_date'];
-            $piggyBank->start_date_tz = $data['target_date']?->format('e');
+            $piggyBank->start_date_tz = $data['start_date']?->format('e');
         }
         $piggyBank->save();
 
diff --git a/app/Support/JsonApi/Enrichments/PiggyBankEnrichment.php b/app/Support/JsonApi/Enrichments/PiggyBankEnrichment.php
index 48b51a33ef..24f4663e7f 100644
--- a/app/Support/JsonApi/Enrichments/PiggyBankEnrichment.php
+++ b/app/Support/JsonApi/Enrichments/PiggyBankEnrichment.php
@@ -163,6 +163,7 @@ class PiggyBankEnrichment implements EnrichmentInterface
             }
 
             // get suggested per month.
+
             $meta['save_per_month']    = Steam::bcround(
                 $this->getSuggestedMonthlyAmount($this->date, $item->target_date, $meta['target_amount'], $meta['current_amount']),
                 $currency->decimal_places
@@ -295,6 +296,7 @@ class PiggyBankEnrichment implements EnrichmentInterface
 
     /**
      * Returns the suggested amount the user should save per month, or "".
+     * TODO same as in repository.
      */
     private function getSuggestedMonthlyAmount(?Carbon $startDate, ?Carbon $targetDate, ?string $targetAmount, string $currentAmount): string
     {
@@ -303,8 +305,7 @@ class PiggyBankEnrichment implements EnrichmentInterface
         }
         $savePerMonth = '0';
         if (1 === bccomp($targetAmount, $currentAmount)) {
-            $now             = today(config('app.timezone'));
-            $diffInMonths    = (int) $startDate->diffInMonths($targetDate);
+            $diffInMonths    = ceil($startDate->diffInMonths($targetDate));
             $remainingAmount = bcsub($targetAmount, $currentAmount);
 
             // more than 1 month to go and still need money to save: