diff --git a/manual_trading_hub/static/chart_draw.js b/manual_trading_hub/static/chart_draw.js
index ffa43f2..f40e831 100644
--- a/manual_trading_hub/static/chart_draw.js
+++ b/manual_trading_hub/static/chart_draw.js
@@ -410,27 +410,24 @@
     ctx.restore();
   }
 
-  /** OKX 期权到期:每周五 08:00 UTC(=北京 16:00) */
+  /** OKX 期权到期切日:每天 08:00 UTC(=北京 16:00),对应日期权 1/2/3 日间隔 */
   function collectOptionExpiryBoundaries(candles) {
     if (!candles.length) return [];
     const minT = Number(candles[0].time);
     const maxT = Number(candles[candles.length - 1].time);
     if (!Number.isFinite(minT) || !Number.isFinite(maxT)) return [];
+    // 北京日历日 → UTC 当天 08:00(=北京 16:00)
+    const minP = utcSecToBjParts(minT);
+    const maxP = utcSecToBjParts(maxT);
     const out = [];
-    const cur = new Date(minT * 1000);
-    cur.setUTCHours(0, 0, 0, 0);
-    cur.setUTCDate(cur.getUTCDate() - 1);
-    const endSec = maxT + 2 * 86400;
-    while (cur.getTime() / 1000 <= endSec) {
-      if (cur.getUTCDay() === 5) {
-        const boundary = Math.floor(
-          Date.UTC(cur.getUTCFullYear(), cur.getUTCMonth(), cur.getUTCDate(), 8, 0, 0) / 1000
-        );
-        if (boundary >= minT - 3600 && boundary <= maxT + 3600) {
-          if (!out.length || out[out.length - 1] !== boundary) out.push(boundary);
-        }
+    let curMs = Date.UTC(minP.y, minP.m, minP.d, 8, 0, 0) - 86400000;
+    const endMs = Date.UTC(maxP.y, maxP.m, maxP.d, 8, 0, 0) + 2 * 86400000;
+    while (curMs <= endMs) {
+      const boundary = Math.floor(curMs / 1000);
+      if (boundary >= minT - 3600 && boundary <= maxT + 3600) {
+        if (!out.length || out[out.length - 1] !== boundary) out.push(boundary);
       }
-      cur.setUTCDate(cur.getUTCDate() + 1);
+      curMs += 86400000;
     }
     return out;
   }
diff --git a/manual_trading_hub/static/index.html b/manual_trading_hub/static/index.html
index ea1d244..adef8dd 100644
--- a/manual_trading_hub/static/index.html
+++ b/manual_trading_hub/static/index.html
@@ -324,7 +324,7 @@
               <label class="market-day-split-opt" title="北京时间 8:00 交易切日竖线">
                 <input type="checkbox" id="market-day-split" /> 交易间隔日
               </label>
-              <label class="market-day-split-opt" title="OKX 期权到期:每周五 08:00 UTC(北京 16:00) 黄虚线">
+              <label class="market-day-split-opt" title="OKX 期权到期切日:每天北京 16:00(UTC 08:00) 黄虚线,对应 1/2/3 日期权">
                 <input type="checkbox" id="market-option-expiry-split" /> 期权间隔日
               </label>
               <details class="market-ind-menu">
@@ -1396,8 +1396,8 @@
 
   <div id="toast"></div>
   <script src="https://unpkg.com/lightweight-charts@4.2.0/dist/lightweight-charts.standalone.production.js"></script>
-  <script src="/assets/chart_draw.js?v=20260720-option-expiry-split"></script>
-  <script src="/assets/chart.js?v=20260720-option-expiry-split"></script>
+  <script src="/assets/chart_draw.js?v=20260720-option-day-1600"></script>
+  <script src="/assets/chart.js?v=20260720-option-day-1600"></script>
   <script src="/assets/plan.js?v=20260720-autofill"></script>
   <script src="/assets/calculator.js?v=20260715-calc-tabs"></script>
   <script src="/assets/trade_stats_calendar.js?v=3"></script>