diff --git a/frontend/src/views/paper/New.vue b/frontend/src/views/paper/New.vue
index 44cfadb..044332a 100644
--- a/frontend/src/views/paper/New.vue
+++ b/frontend/src/views/paper/New.vue
@@ -153,6 +153,11 @@ async function onSubmit(): Promise<void> {
     }
     // 影子模式:engine=shadow(VPS 柜台盘中实时撮合);其余 eod_replay(回放/日终)
     payload.engine = payload.mode === 'shadow' ? 'shadow' : 'eod_replay'
+    // 实走/影子是开放账户:起止日期无意义,开始=创建当天,结束留空(回放才需要历史区间)
+    if (payload.mode !== 'replay') {
+      payload.start = new Date().toISOString().slice(0, 10)
+      payload.end = ''
+    }
     const aid = await createPaper(payload)
     ElMessage.success(payload.mode === 'shadow'
       ? `已创建影子柜台模拟盘 #${aid}（VPS 柜台运行期间盘中实时结算）`
@@ -284,18 +289,25 @@ function onSymbols(v: string): void {
     </el-card>
 
     <el-card class="blk" shadow="never">
-      <template #header><span class="section-title">资金与区间</span></template>
+      <template #header>
+        <span class="section-title">{{ form.mode === 'replay' ? '资金与区间' : '资金' }}</span>
+      </template>
       <el-form :model="form" label-width="120px">
         <el-form-item label="起始资金">
           <el-input-number v-model="form.initial_capital" :min="10000" :step="100000" style="width: 220px" />
           <span class="muted form-hint">单位：元</span>
         </el-form-item>
-        <el-form-item label="开始日期">
-          <el-date-picker v-model="form.start" type="date" value-format="YYYY-MM-DD" style="width: 220px" />
-        </el-form-item>
-        <el-form-item label="结束日期">
-          <el-date-picker v-model="form.end" type="date" value-format="YYYY-MM-DD" style="width: 220px" />
-        </el-form-item>
+        <template v-if="form.mode === 'replay'">
+          <el-form-item label="开始日期">
+            <el-date-picker v-model="form.start" type="date" value-format="YYYY-MM-DD" style="width: 220px" />
+          </el-form-item>
+          <el-form-item label="结束日期">
+            <el-date-picker v-model="form.end" type="date" value-format="YYYY-MM-DD" style="width: 220px" />
+          </el-form-item>
+        </template>
+        <div v-else class="muted" style="font-size: 12px; margin: -8px 0 4px">
+          {{ form.mode === 'shadow' ? '影子柜台从创建当天开始实时跟踪，无结束日期' : '每日 20:30 从创建当天开始结算，无结束日期' }}
+        </div>
       </el-form>
     </el-card>
 
diff --git a/sanguo_api/routes_paper.py b/sanguo_api/routes_paper.py
index 47267c0..1712984 100644
--- a/sanguo_api/routes_paper.py
+++ b/sanguo_api/routes_paper.py
@@ -70,6 +70,13 @@ def create_paper(req: PaperCreateRequest):
 
     db = _db_path["path"] or ":memory:"
     init_db(db)
+    # 实走/影子是开放账户:起止日期无意义,开始=创建当天(组合日终重放依赖 start_date,
+    # 空值会崩),结束留空;仅回放保留用户填的历史区间
+    if req.mode in ("live", "shadow"):
+        from datetime import date
+
+        req.start = date.today().isoformat()
+        req.end = ""
     if req.strategy_type == "portfolio":
         if req.mode not in ("live", "shadow"):
             raise HTTPException(400, "组合策略模拟盘仅支持实走(live)/影子(shadow)模式；历史回放请用「组合回测」")
diff --git a/tests/api/test_paper_routes.py b/tests/api/test_paper_routes.py
index 7424d6e..2358be4 100644
--- a/tests/api/test_paper_routes.py
+++ b/tests/api/test_paper_routes.py
@@ -63,8 +63,14 @@ def test_create_shadow_mode(tmp_path):
     cta = by_id[r1.json()["account_id"]]
     assert cta["mode"] == "shadow"
     assert cta["engine"] == "shadow"
+    # 实走/影子是开放账户:用户填的区间被忽略,开始=创建当天,结束留空
+    from datetime import date
+
+    assert cta["start_date"] == date.today().isoformat()
+    assert not cta["end_date"]
     pf = by_id[r2.json()["account_id"]]
     assert pf["mode"] == "shadow" and pf["engine"] == "shadow"
+    assert not pf["end_date"]
 
 
 def test_create_portfolio_rejects_replay(tmp_path):