diff --git a/pro/src/conflictLogic.ts b/pro/src/conflictLogic.ts
index f9744c2..8a3b42b 100644
--- a/pro/src/conflictLogic.ts
+++ b/pro/src/conflictLogic.ts
@@ -167,7 +167,7 @@ export async function mergeFile(
     key,
     newArrayBuffer,
     rightEntity.mtimeCli ?? mtime,
-    rightEntity.mtimeCli ?? mtime
+    rightEntity.ctimeCli ?? rightEntity.mtimeCli ?? mtime
   );
 
   return {
diff --git a/pro/src/fsOnedriveFull.ts b/pro/src/fsOnedriveFull.ts
index 3aaf39f..63c9991 100644
--- a/pro/src/fsOnedriveFull.ts
+++ b/pro/src/fsOnedriveFull.ts
@@ -294,13 +294,21 @@ const fromDriveItemToEntity = (x: DriveItem, remoteBaseDir: string): Entity => {
   if (mtimeTry === undefined || mtimeTry === null) {
     throw Error(`onedrive cannot parse mtime: ${JSON.stringify(x, null, 2)}`);
   }
+  let ctimeTry = x?.fileSystemInfo?.createdDateTime;
+  if (ctimeTry === undefined || ctimeTry === null) {
+    // throw Error(`onedrive cannot parse ctime: ${JSON.stringify(x, null, 2)}`);
+    // it doesn't hurt, we just use mtimeTry to fullfill
+    ctimeTry = mtimeTry;
+  }
   const mtimeSvr = Date.parse(mtimeTry);
   const mtimeCli = Date.parse(mtimeTry);
+  const ctimeCli = Date.parse(ctimeTry);
   return {
     key: key,
     keyRaw: key,
     mtimeSvr: mtimeSvr,
     mtimeCli: mtimeCli,
+    ctimeCli: ctimeCli,
     size: isFolder ? 0 : x.size!,
     sizeRaw: isFolder ? 0 : x.size!,
     synthesizedFile: false,
@@ -771,6 +779,7 @@ export class FakeFsOnedriveFull extends FakeFs {
           keyRaw: origKey,
           mtimeSvr: mtime,
           mtimeCli: mtime,
+          ctimeCli: ctime,
           size: 0,
           sizeRaw: 0,
           synthesizedFile: true,
diff --git a/pro/src/sync.ts b/pro/src/sync.ts
index bef5d91..27b9d51 100644
--- a/pro/src/sync.ts
+++ b/pro/src/sync.ts
@@ -60,6 +60,17 @@ const copyEntityAndFixTimeFormat = (
       result.mtimeCliFmt = unixTimeToStr(result.mtimeCli);
     }
   }
+  if (result.ctimeCli !== undefined) {
+    if (result.ctimeCli === 0) {
+      result.ctimeCli = undefined;
+    } else {
+      if (serviceType === "s3" || serviceType === "dropbox") {
+        // round to second instead of millisecond
+        result.ctimeCli = Math.floor(result.ctimeCli / 1000.0) * 1000;
+      }
+      result.ctimeCliFmt = unixTimeToStr(result.ctimeCli);
+    }
+  }
   if (result.mtimeSvr !== undefined) {
     if (result.mtimeSvr === 0) {
       result.mtimeSvr = undefined;
diff --git a/src/baseTypes.ts b/src/baseTypes.ts
index 8fb559f..2f86ca3 100644
--- a/src/baseTypes.ts
+++ b/src/baseTypes.ts
@@ -271,6 +271,8 @@ export interface Entity {
   keyRaw: string;
   mtimeCli?: number;
   mtimeCliFmt?: string;
+  ctimeCli?: number;
+  ctimeCliFmt?: string;
   mtimeSvr?: number;
   mtimeSvrFmt?: string;
   prevSyncTime?: number;
diff --git a/src/copyLogic.ts b/src/copyLogic.ts
index 851fe8a..5816bbc 100644
--- a/src/copyLogic.ts
+++ b/src/copyLogic.ts
@@ -41,7 +41,7 @@ export async function copyFile(key: string, left: FakeFs, right: FakeFs) {
       key,
       content,
       statsLeft.mtimeCli,
-      statsLeft.mtimeCli /* TODO */
+      statsLeft.ctimeCli ?? statsLeft.mtimeCli
     ),
     content: content,
   };
diff --git a/src/fsLocal.ts b/src/fsLocal.ts
index 54e7751..ae7be28 100644
--- a/src/fsLocal.ts
+++ b/src/fsLocal.ts
@@ -133,8 +133,10 @@ export class FakeFsLocal extends FakeFs {
     return {
       key: isFolder ? `${key}/` : key, // local always unencrypted
       keyRaw: isFolder ? `${key}/` : key,
+      ctimeCli: statRes.ctime,
       mtimeCli: statRes.mtime,
       mtimeSvr: statRes.mtime,
+      ctimeCliFmt: unixTimeToStr(statRes.ctime),
       mtimeCliFmt: unixTimeToStr(statRes.mtime),
       mtimeSvrFmt: unixTimeToStr(statRes.mtime),
       size: statRes.size, // local always unencrypted
diff --git a/src/fsOnedrive.ts b/src/fsOnedrive.ts
index 19a087b..e64e8c0 100644
--- a/src/fsOnedrive.ts
+++ b/src/fsOnedrive.ts
@@ -403,13 +403,23 @@ ${constructFromDriveItemToEntityError(x)}`
   if (mtimeTry === undefined || mtimeTry === null) {
     throw Error(`onedrive cannot parse mtime: ${JSON.stringify(x, null, 2)}`);
   }
+
+  let ctimeTry = x?.fileSystemInfo?.createdDateTime;
+  if (ctimeTry === undefined || ctimeTry === null) {
+    // throw Error(`onedrive cannot parse ctime: ${JSON.stringify(x, null, 2)}`);
+    // it doesn't hurt, we just use mtimeTry to fullfill
+    ctimeTry = mtimeTry;
+  }
+
   const mtimeSvr = Date.parse(mtimeTry);
   const mtimeCli = Date.parse(mtimeTry);
+  const ctimeCli = Date.parse(ctimeTry);
   return {
     key: key,
     keyRaw: key,
     mtimeSvr: mtimeSvr,
     mtimeCli: mtimeCli,
+    ctimeCli: ctimeCli,
     size: isFolder ? 0 : x.size!,
     sizeRaw: isFolder ? 0 : x.size!,
     synthesizedFile: false,
@@ -878,6 +888,7 @@ export class FakeFsOnedrive extends FakeFs {
           keyRaw: origKey,
           mtimeSvr: mtime,
           mtimeCli: mtime,
+          ctimeCli: ctime,
           size: 0,
           sizeRaw: 0,
           synthesizedFile: true,