diff --git a/src/resources/plugins/TsSheet/form/component/formdate.vue b/src/resources/plugins/TsSheet/form/component/formdate.vue
index 6134981fe0ad3108462cdccc90dbb784bae2aa00..d717aa71ad42cef46643f1bbd545d1dd0960fcb0 100644
--- a/src/resources/plugins/TsSheet/form/component/formdate.vue
+++ b/src/resources/plugins/TsSheet/form/component/formdate.vue
@@ -298,7 +298,7 @@ export default {
       }
     },
     getValidateList() {
-      let validateList = this.validateList;
+      let validateList = this.$utils.deepClone(this.validateList || []);
       let dateText = {
         later: this.$t('term.framework.later'),
         earlier: this.$t('term.framework.earlier'),