diff --git a/packages/common/components/src/ui/date-picker/index.tsx b/packages/common/components/src/ui/date-picker/index.tsx
index 85c584e5f..67265df0e 100644
--- a/packages/common/components/src/ui/date-picker/index.tsx
+++ b/packages/common/components/src/ui/date-picker/index.tsx
@@ -40,8 +40,10 @@ export function DatePicker({
         </Button>
       </PopoverTrigger>
       <PopoverContent
-        className="w-auto p-0"
-        style={{ zIndex: zIndex || 'auto' }}
+        className={cn(
+          "w-auto p-0",
+          zIndex ? `z-[${zIndex}]` : "" // zIndex가 있으면 적용, 없으면 기본값
+        )}
       >
         <Calendar classNames={{ cell: "rounded-md" }} {...props} />
       </PopoverContent>