diff --git a/src/components/GanttChart/GanttChart.vue b/src/components/GanttChart/GanttChart.vue
index af1a759ed1ae2f8f82242ff60eb4c94ef192ab1c..15b616fc751d69167c65c2a8edfe9a6518f47516 100644
--- a/src/components/GanttChart/GanttChart.vue
+++ b/src/components/GanttChart/GanttChart.vue
@@ -219,8 +219,7 @@ function clearOriginalMaps() {
 
 function convertToLocalTime(utcString: string): string {
   const date = new Date(utcString)
-  date.setHours(date.getHours() + 7)
-  return date.toISOString().slice(0, 16).replace('T', ' ')
+  return date.toLocaleString("th-TH", { timeZone: "Asia/Bangkok" })
 }
 
 // Pagination & Dialog