[FIX] 예상 작업 완료 시간 관련 로직 수정

src/lib/buildProcessSteps.tsx

@@ -15,7 +15,7 @@ import {
 import { ActionButton } from "@/components/photoManage/ActionButton";
 import { RecipientInfoCard } from "@/components/photoManage/RecipientInfoCard";
 import { formatEstimatedTime, formatShippedDate } from "@/utils/dateFormat";
-import { getEarlyFinishedHours } from "@/utils/getEarlyFinishedHours";
+import { getEarlyFinishedTime } from "@/utils/getEarlyFinishedTime";
 import ProcessStepSubContent from "@/components/photoManage/ProcessStepSubContent";
 
 type BuildStepsArgs = {
@@ -48,7 +48,7 @@ export function buildProcessSteps({
   };
 
   const earlyHours = workData.print
-    ? getEarlyFinishedHours(
+    ? getEarlyFinishedTime(
         workData.print.estimatedAt,
         workData.print.completedAt,
       )
@@ -129,11 +129,14 @@ export function buildProcessSteps({
       workData.print?.status === "COMPLETED"
     ) {
       const content = `작업 완료 시간: ${formatEstimatedTime(workData.print.completedAt)}`;
-      const subcontent = `예상 작업 시간보다 ${earlyHours}시간 빨리 완료되었어요!`;
       return (
         <ProcessStepSubContent
           content={content}
-          subcontent={subcontent}
+          subcontent={
+            earlyHours !== -1
+              ? `예상 작업 시간보다 ${earlyHours} 빨리 완료되었어요!`
+              : undefined
+          }
           icon={<ClockIcon className="h-3 w-3" />}
         />
       );

src/utils/getEarlyFinishedTime.ts

@@ -0,0 +1,34 @@
+export function getEarlyFinishedTime(
+  estimatedAt: string | null,
+  completedAt: string | null,
+): string {
+  if (!estimatedAt || !completedAt) return "";
+
+  const estimated = new Date(estimatedAt).getTime();
+  const completed = new Date(completedAt).getTime();
+
+  const diffMs = estimated - completed;
+
+  // 일찍 끝나지 않았으면
+  if (diffMs <= 0) return "-1";
+
+  const totalMinutes = Math.floor(diffMs / (1000 * 60));
+
+  const minutesInHour = 60;
+  const minutesInDay = 60 * 24;
+
+  // 1시간 미만 → 분
+  if (totalMinutes < minutesInHour) {
+    return `${totalMinutes}분`;
+  }
+
+  // 1일 미만 → 시간
+  if (totalMinutes < minutesInDay) {
+    const hours = Math.floor(totalMinutes / minutesInHour);
+    return `${hours}시간`;
+  }
+
+  // 1일 이상 → 일
+  const days = Math.floor(totalMinutes / minutesInDay);
+  return `${days}일`;
+}