diff --git a/src/app/parent/actions.ts b/src/app/parent/actions.ts
index b76f166..ec622b1 100644
--- a/src/app/parent/actions.ts
+++ b/src/app/parent/actions.ts
@@ -79,8 +79,8 @@ const templateSchema = z.object({
   dow: z.coerce.number().int().min(0).max(6).catch(0),
   subject: z.enum(SUBJECT_VALUES).catch("other"),
   mode: z.enum(["weekly", "date", "range", "week"]).catch("weekly"),
-  dateStart: z.string().optional(),
-  dateEnd: z.string().optional(),
+  dateStart: z.string().nullish(),
+  dateEnd: z.string().nullish(),
   title: z.string().trim().min(1, "任务内容不能为空").max(100, "最多 100 字"),
   requiresPhoto: z.boolean(),
 });