diff --git a/FrontendWebApi/ApiControllers/HydroMeterController.cs b/FrontendWebApi/ApiControllers/HydroMeterController.cs
index d30325a..214b5e0 100644
--- a/FrontendWebApi/ApiControllers/HydroMeterController.cs
+++ b/FrontendWebApi/ApiControllers/HydroMeterController.cs
@@ -981,7 +981,7 @@ namespace FrontendWebApi.ApiControllers
                 row = sheet.GetRow(rowInit++) ?? sheet.CreateRow(rowInit++);
                 colInit = 0;
                 cell = row.GetCell(colInit++) ?? row.CreateCell(colInit++);
-                DateTime timeDay = date.AddMonths(1).AddDays(-1); // 用來記錄每個月的最後一天是幾月幾號
+                DateTime timeDay = DateTime.Parse(input.startTime).AddMonths(1).AddDays(-1); // 用來記錄每個月的最後一天是幾月幾號
                 string timeRange = start_year + "." + start_month + ".01~" + timeDay.ToString("yyy.MM.dd");
                 cell.SetCellValue("電錶週期：" + timeRange);