diff --git a/public/viewjs/purchase.js b/public/viewjs/purchase.js
index 453f4057..78368475 100644
--- a/public/viewjs/purchase.js
+++ b/public/viewjs/purchase.js
@@ -288,19 +288,20 @@ if (Grocy.Components.ProductPicker !== undefined)
 
 					if (Grocy.FeatureFlags.GROCY_FEATURE_FLAG_STOCK_BEST_BEFORE_DATE_TRACKING)
 					{
-						var best_before;
-						if (productDetails.location.is_freezer.toString() == "1")
+						var dueDays;
+						if (Grocy.FeatureFlags.GROCY_FEATURE_FLAG_STOCK_PRODUCT_FREEZING && BoolVal(productDetails.location.is_freezer))
 						{
-							best_before = productDetails.product.default_best_before_days_after_freezing;
+							dueDays = productDetails.product.default_best_before_days_after_freezing;
 						}
 						else
 						{
-							best_before = productDetails.product.default_best_before_days;
+							dueDays = productDetails.product.default_best_before_days;
 						}
 
-						if (best_before.toString() !== '0')
+						dueDays = parseFloat(dueDays);
+						if (dueDays != 0)
 						{
-							if (best_before == -1)
+							if (dueDays == -1)
 							{
 								if (!$("#datetimepicker-shortcut").is(":checked"))
 								{
@@ -309,7 +310,7 @@ if (Grocy.Components.ProductPicker !== undefined)
 							}
 							else
 							{
-								Grocy.Components.DateTimePicker.SetValue(moment().add(best_before, 'days').format('YYYY-MM-DD'));
+								Grocy.Components.DateTimePicker.SetValue(moment().add(dueDays, 'days').format('YYYY-MM-DD'));
 							}
 						}
 					}
diff --git a/services/StockService.php b/services/StockService.php
index 98aaca8b..79796f97 100644
--- a/services/StockService.php
+++ b/services/StockService.php
@@ -147,13 +147,15 @@ class StockService extends BaseService
 			if ($locationId !== null && !$this->LocationExists($locationId))
 			{
 				throw new \Exception('Location does not exist');
-			} else {
+			}
+			else
+			{
 				$location = $this->getDatabase()->locations()->where('id', $locationId)->fetch();
 			}
 
-			if (GROCY_FEATURE_FLAG_STOCK_PRODUCT_FREEZING && $locationId !== null && intval($location->is_freezer) === 1 && $productDetails->product->default_best_before_days_after_freezing >= -1)
+			if (GROCY_FEATURE_FLAG_STOCK_PRODUCT_FREEZING && $locationId !== null && intval($location->is_freezer) === 1 && intval($productDetails->product->default_best_before_days_after_freezing) >= -1)
 			{
-				if ($productDetails->product->default_best_before_days_after_freezing == -1)
+				if (intval($productDetails->product->default_best_before_days_after_freezing) == -1)
 				{
 					$bestBeforeDate = date('2999-12-31');
 				}
@@ -161,7 +163,8 @@ class StockService extends BaseService
 				{
 					$bestBeforeDate = date('Y-m-d', strtotime('+' . $productDetails->product->default_best_before_days_after_freezing . ' days'));
 				}
-			} elseif (intval($productDetails->product->default_best_before_days) == -1)
+			}
+			elseif (intval($productDetails->product->default_best_before_days) == -1)
 			{
 				$bestBeforeDate = date('2999-12-31');
 			}