diff --git a/src/components/OptForm.vue b/src/components/OptForm.vue
index e332e15..b218e95 100644
--- a/src/components/OptForm.vue
+++ b/src/components/OptForm.vue
@@ -26,7 +26,7 @@ onMounted(async () => {
   const data = resp.data.value.data
   mapping.value = data
   options.mapping = data
-  const date = Object.keys(data)[0]
+  const date = Object.keys(data)[Object.keys(data).length - 1]
   const newDateStr = `${date.slice(0, 4)}-${date.slice(4, 6)}-${date.slice(6, 8)}`
 
   if (castBeginDate.value === undefined) {