diff --git a/app/Repositories/Bill/BillRepository.php b/app/Repositories/Bill/BillRepository.php
index 5c4f2b806c..abc6c05412 100644
--- a/app/Repositories/Bill/BillRepository.php
+++ b/app/Repositories/Bill/BillRepository.php
@@ -458,7 +458,7 @@ class BillRepository implements BillRepositoryInterface
             //Log::debug(sprintf('Dates = %d, journalCount = %d, total = %d', $dates->count(), $count, $total));
 
             if ($total > 0) {
-                $average             = bcdiv(bcadd($bill->amount_max, $bill->amount_min), '2');
+                $average             = bcdiv(bcadd((string) $bill->amount_max, (string) $bill->amount_min), '2');
                 $multi               = bcmul($average, (string) $total);
                 $return[$currencyId] = $return[$currencyId] ?? '0';
                 $return[$currencyId] = bcadd($return[$currencyId], $multi);
diff --git a/app/Repositories/PiggyBank/PiggyBankRepository.php b/app/Repositories/PiggyBank/PiggyBankRepository.php
index 9acd034ec8..e74d486dd3 100644
--- a/app/Repositories/PiggyBank/PiggyBankRepository.php
+++ b/app/Repositories/PiggyBank/PiggyBankRepository.php
@@ -341,7 +341,8 @@ class PiggyBankRepository implements PiggyBankRepositoryInterface
         }
         if (null !== $piggyBank->targetdate && $repetition->currentamount < $piggyBank->targetamount) {
             $now             = Carbon::now();
-            $diffInMonths    = $now->diffInMonths($piggyBank->targetdate, false);
+            $startDate       = null !== $piggyBank->startdate && $piggyBank->startdate->gte($now) ? $piggyBank->startdate : $now;
+            $diffInMonths    = $startDate->diffInMonths($piggyBank->targetdate, false);
             $remainingAmount = bcsub($piggyBank->targetamount, $repetition->currentamount);
 
             // more than 1 month to go and still need money to save:
diff --git a/app/Transformers/TransactionGroupTransformer.php b/app/Transformers/TransactionGroupTransformer.php
index 553c03ef5d..6868f45957 100644
--- a/app/Transformers/TransactionGroupTransformer.php
+++ b/app/Transformers/TransactionGroupTransformer.php
@@ -353,7 +353,7 @@ class TransactionGroupTransformer extends AbstractTransformer
         $source          = $this->getSourceTransaction($journal);
         $destination     = $this->getDestinationTransaction($journal);
         $type            = $journal->transactionType->type;
-        $amount          = $this->getAmount($type, $source->amount);
+        $amount          = $this->getAmount($type, (string) $source->amount);
         $foreignAmount   = $this->getForeignAmount($type, $source->foreign_amount);
         $metaFieldData   = $this->groupRepos->getMetaFields($journal->id, $this->metaFields);
         $metaDates       = $this->getDates($this->groupRepos->getMetaDateFields($journal->id, $this->metaDateFields));