diff --git a/backend/app/api/v1/endpoints/analytics.py b/backend/app/api/v1/endpoints/analytics.py
index 24a917c..b51506d 100644
--- a/backend/app/api/v1/endpoints/analytics.py
+++ b/backend/app/api/v1/endpoints/analytics.py
@@ -40,12 +40,16 @@ async def flow_compare(
     product_sns: str | None = Query(None, description="身份证，逗号分隔"),
     spec_models: str | None = Query(None, description="规格型号，逗号分隔（无 product_sns 时按型号取最近设备）"),
     mode: str = Query("natural", description="时间口径: natural(自然小时) / workdays(工作小时,排除周末节假日)"),
+    since: str | None = Query(None, description="起始日期 ISO"),
+    until: str | None = Query(None, description="截止日期 ISO"),
     db: AsyncSession = Depends(get_db),
 ):
     """设备流转对比 — 每台设备各操作人耗时（堆叠柱状，按人堆叠，识别瓶颈）。"""
     sns = [s.strip() for s in product_sns.split(",") if s.strip()] if product_sns else None
     specs = [s.strip() for s in spec_models.split(",") if s.strip()] if spec_models else None
-    return await get_flow_compare(db, product_sns=sns, spec_models=specs, mode=mode)
+    since_dt = datetime.fromisoformat(since) if since else None
+    until_dt = datetime.fromisoformat(until) if until else None
+    return await get_flow_compare(db, product_sns=sns, spec_models=specs, mode=mode, since=since_dt, until=until_dt)
 
 
 @router.get("/options", response_model=AnalyticsOptions)
diff --git a/backend/app/services/analytics_service.py b/backend/app/services/analytics_service.py
index c7e218f..dbcb53a 100644
--- a/backend/app/services/analytics_service.py
+++ b/backend/app/services/analytics_service.py
@@ -285,6 +285,8 @@ async def get_flow_compare(
     product_sns: list[str] | None = None,
     spec_models: list[str] | None = None,
     mode: str = "natural",
+    since: datetime | None = None,
+    until: datetime | None = None,
 ) -> FlowResponse:
     """
     查询每台设备上各操作人的任务时间区间，拼装为「生命周期时间轴」区间图：
@@ -296,7 +298,11 @@ async def get_flow_compare(
       - 仅传 spec_models：这些型号下最近有流转的 20 台设备；
       - 都未传：返回空。
 
-    data 每项 = [device_index, start_offset, end_offset, task_name, duration]（单位小时）。
+    data 每项 = [device_index, task_name, is_main,
+                 start_nat, end_nat, start_work, end_work,
+                 duration_total(自然), duration_work(工作日)]（单位小时）。
+    前端按 isWorkday 切换选取自然/工作日偏移，即时重绘无需重新请求。
+    mode 参数保留兼容（历史调用），不再影响返回内容。
     """
     from app.models.task import Task, TASK_STATUS_WIP, TASK_STATUS_PENDING, TASK_STATUS_COMPLETED
     from app.models.product import Product
@@ -382,6 +388,11 @@ async def get_flow_compare(
         end = _to_bj(completed_at) if completed_at else now
         if start is None:
             continue
+        # 时间筛选：任务区间与 [since, until] 有交集
+        if since is not None and end is not None and end < since:
+            continue
+        if until is not None and start is not None and start > until:
+            continue
         is_main = 0 if task_type == "SPAWN" else 1
         intervals.append({
             "idx": idx,
@@ -430,24 +441,23 @@ async def get_flow_compare(
     ]
 
     # ── 按人分组，转为相对 T0 的小时偏移区间 ──
+    # 每项同时携带自然天与工作日两套偏移/时长，供前端按 isWorkday 即时切换：
+    #   [idx, task_name, is_main, start_nat, end_nat, start_work, end_work, dur_total, dur_work]
+    from app.core.time_utils import working_duration_hours as _wdh
+    from app.models.holiday import Holiday as _Holiday
+    hres = await db.execute(select(_Holiday.day))
+    _holidays = {r[0] for r in hres}
     by_assignee: dict[str, list[list]] = {}
-    # 工作日模式：把时间偏移换算为「排除周末/节假日的工作小时」，压缩休息日
-    if mode == "workdays":
-        from app.core.time_utils import working_duration_hours as _wdh
-        from app.models.holiday import Holiday as _Holiday
-        hres = await db.execute(select(_Holiday.day))
-        _holidays = {r[0] for r in hres}
     for it in intervals:
         t0 = t0_by_device[it["idx"]]
-        if mode == "workdays":
-            start_offset = _wdh(t0, it["start"], _holidays)
-            end_offset = _wdh(t0, it["end"], _holidays)
-        else:
-            start_offset = round((it["start"] - t0).total_seconds() / 3600, 1)
-            end_offset = round((it["end"] - t0).total_seconds() / 3600, 1)
-        duration = round(end_offset - start_offset, 1)
+        start_nat = round((it["start"] - t0).total_seconds() / 3600, 1)
+        end_nat = round((it["end"] - t0).total_seconds() / 3600, 1)
+        start_work = round(_wdh(t0, it["start"], _holidays), 1)
+        end_work = round(_wdh(t0, it["end"], _holidays), 1)
         by_assignee.setdefault(it["assignee_id"], []).append(
-            [it["idx"], start_offset, end_offset, it["task_name"], duration, it["is_main"]]
+            [it["idx"], it["task_name"], it["is_main"],
+             start_nat, end_nat, start_work, end_work,
+             round(end_nat - start_nat, 1), round(end_work - start_work, 1)]
         )
 
     # 翻译人员姓名