diff --git a/apps/web/components/version/PlanTab.tsx b/apps/web/components/version/PlanTab.tsx
index edad12d..de0d817 100644
--- a/apps/web/components/version/PlanTab.tsx
+++ b/apps/web/components/version/PlanTab.tsx
@@ -55,13 +55,20 @@ export function PlanTab({ plans, versionId, versionDeadline, currentUserName, pl
       ) : (
         <div className="space-y-3">
           {typePlans.map((plan) => {
-            // 已耗时：已完成用实际完成时间，进行中用当前时间，未开始为0
-            const now = new Date().toISOString().slice(0, 10);
-            const effectiveStatus = plan.status === 'pending' && plan.startTime <= now ? 'in_progress' : plan.status;
-            const dur = effectiveStatus === 'completed' && plan.completedAt
-              ? calcPlanDuration(plan.startTime, plan.completedAt)
-              : effectiveStatus === 'in_progress'
-                ? calcPlanDuration(plan.startTime, now)
+            const now = new Date().toISOString();
+            const nowDate = now.slice(0, 10);
+            // 自动进入进行中（到了计划开始日期）
+            const shouldAutoStart = plan.status === 'pending' && plan.startTime <= nowDate;
+            if (shouldAutoStart && !plan.actualStartAt) {
+              onUpdate(plan.id, { status: 'in_progress' });
+            }
+            const effectiveStatus = shouldAutoStart ? 'in_progress' : plan.status;
+            // 耗时用实际时间戳计算
+            const actualStart = plan.actualStartAt || (shouldAutoStart ? now : null);
+            const dur = effectiveStatus === 'completed' && plan.completedAt && actualStart
+              ? calcPlanDuration(actualStart, plan.completedAt)
+              : effectiveStatus === 'in_progress' && actualStart
+                ? calcPlanDuration(actualStart, now)
                 : { days: 0, hours: 0 };
             const durText = dur.days > 0 || dur.hours > 0 ? formatDuration(dur.days, dur.hours) : '-';
             return (
@@ -76,7 +83,8 @@ export function PlanTab({ plans, versionId, versionDeadline, currentUserName, pl
                     </div>
                     <div className="flex items-center gap-4 text-[12px] text-[var(--ink-soft)]">
                       <span>计划：{plan.startTime.slice(0, 10)} → {plan.endTime.slice(0, 10)}</span>
-                      {plan.completedAt && <span className="text-green-600">完成：{plan.completedAt.slice(0, 10)}</span>}
+                      {plan.actualStartAt && <span className="text-blue-600">实际开始：{plan.actualStartAt.slice(0, 16).replace('T', ' ')}</span>}
+                      {plan.completedAt && <span className="text-green-600">完成：{plan.completedAt.slice(0, 16).replace('T', ' ')}</span>}
                       <span className="font-medium text-[var(--ink)]">已耗时 {durText}</span>
                     </div>
                     {plan.overdueReason && (
diff --git a/apps/web/lib/version-plan.ts b/apps/web/lib/version-plan.ts
index b64b809..0891620 100644
--- a/apps/web/lib/version-plan.ts
+++ b/apps/web/lib/version-plan.ts
@@ -48,12 +48,14 @@ export function calcPlanDuration(start: string, end: string): { days: number; ho
   const s = new Date(start).getTime();
   const e = new Date(end).getTime();
   if (isNaN(s) || isNaN(e) || e < s) return { days: 0, hours: 0 };
-  const diff = Math.ceil((e - s) / (1000 * 60 * 60 * 24));
-  const totalDays = Math.max(1, diff); // 当天开始当天结束至少1天
-  return { days: totalDays, hours: totalDays * 8 };
+  const diffHours = (e - s) / (1000 * 60 * 60);
+  const hours = Math.round(diffHours * 2) / 2; // 精确到0.5h
+  const days = Math.ceil(diffHours / 24);
+  return { days, hours };
 }
 
-export function formatDuration(days: number, _hours: number): string {
+export function formatDuration(days: number, hours: number): string {
+  if (hours > 0) return `${hours}h`;
   if (days === 0) return '0天';
   return `${days}天`;
 }