BMS计费单据审核计费流水周期开始时间修改

mhd_bms/src/main/java/com/mhd/bms/domain/billingStatement/service/BillingStatementDomainService.java

@@ -538,8 +538,9 @@ public class BillingStatementDomainService {
             currentMonthPaymentDate = DateUtil.offsetDay(currentMonthPaymentDate, paymentDay - 1);
             // 结束时间：本月出账日的前一天
             Date cycleEndTime = DateUtil.offsetDay(currentMonthPaymentDate, -1);
-            // 开始时间：上个月的出账日
-            Date cycleBeginTime = DateUtil.offsetMonth(currentMonthPaymentDate, -1);
+            // 开始时间：上个月的出账日（明确计算上个月的第一天，然后加上出账日-1天）
+            Date lastMonthFirstDay = DateUtil.beginOfMonth(DateUtil.offsetMonth(businessDate, -1));
+            Date cycleBeginTime = DateUtil.offsetDay(lastMonthFirstDay, paymentDay - 1);
             
             billingStatementDO.setCycleBeginTime(cycleBeginTime);
             billingStatementDO.setCycleEndTime(cycleEndTime);