diff --git a/src/apptask.js b/src/apptask.js
index 8cc0654a0..b95bc37d0 100644
--- a/src/apptask.js
+++ b/src/apptask.js
@@ -410,7 +410,7 @@ function backup(app, callback) {
 
     async.series([
         updateApp.bind(null, app, { installationProgress: '10, Backing up' }),
-        backups.backupApp.bind(null, app, app.manifest, null /* tag */),
+        backups.backupApp.bind(null, app, app.manifest, 'appbackups' /* tag */),
 
         // done!
         function (callback) {
@@ -600,7 +600,7 @@ function update(app, callback) {
 
             async.series([
                 updateApp.bind(null, app, { installationProgress: '30, Backing up app' }),
-                backups.backupApp.bind(null, app, app.oldConfig.manifest, null /* tag */)
+                backups.backupApp.bind(null, app, app.oldConfig.manifest, 'appbackups' /* tag */)
             ], next);
         },
 
diff --git a/src/backups.js b/src/backups.js
index b696d1502..23aa89f34 100644
--- a/src/backups.js
+++ b/src/backups.js
@@ -171,15 +171,16 @@ function getRestoreUrl(backupId, callback) {
     });
 }
 
-function copyLastBackup(app, manifest, tag, callback) {
+function copyLastBackup(app, manifest, prefix, callback) {
     assert.strictEqual(typeof app, 'object');
     assert.strictEqual(typeof app.lastBackupId, 'string');
     assert(manifest && typeof manifest === 'object');
-    assert.strictEqual(typeof tag, 'string');
+    assert.strictEqual(typeof prefix, 'string');
     assert.strictEqual(typeof callback, 'function');
 
-    var toFilenameArchive = util.format('%s/app_%s_%s_v%s.tar.gz', tag, app.id, tag, manifest.version);
-    var toFilenameConfig = util.format('%s/app_%s_%s_v%s.json', tag, app.id, tag, manifest.version);
+    var timestamp = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
+    var toFilenameArchive = util.format('%s/app_%s_%s_v%s.tar.gz', prefix, app.id, timestamp, manifest.version);
+    var toFilenameConfig = util.format('%s/app_%s_%s_v%s.json', prefix, app.id, timestamp, manifest.version);
 
     settings.getBackupConfig(function (error, backupConfig) {
         if (error) return callback(new BackupsError(BackupsError.INTERNAL_ERROR, error));
@@ -203,11 +204,12 @@ function copyLastBackup(app, manifest, tag, callback) {
     });
 }
 
-function backupBoxWithAppBackupIds(appBackupIds, tag, callback) {
+function backupBoxWithAppBackupIds(appBackupIds, prefix, callback) {
     assert(util.isArray(appBackupIds));
-    assert.strictEqual(typeof tag, 'string');
+    assert.strictEqual(typeof prefix, 'string');
 
-    var filebase = util.format('%s/box_%s_v%s', tag, tag, config.version());
+    var timestamp = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
+    var filebase = util.format('%s/box_%s_v%s', prefix, timestamp, config.version());
     var filename = filebase + '.tar.gz';
 
     settings.getBackupConfig(function (error, backupConfig) {
@@ -245,13 +247,14 @@ function canBackupApp(app) {
             app.installationState === appdb.ISTATE_PENDING_UPDATE; // called from apptask
 }
 
-function createNewAppBackup(app, manifest, tag, callback) {
+function createNewAppBackup(app, manifest, prefix, callback) {
     assert.strictEqual(typeof app, 'object');
     assert(manifest && typeof manifest === 'object');
-    assert.strictEqual(typeof tag, 'string');
+    assert.strictEqual(typeof prefix, 'string');
     assert.strictEqual(typeof callback, 'function');
 
-    var filebase = util.format('%s/app_%s_%s_v%s', tag, app.id, tag, manifest.version);
+    var timestamp = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
+    var filebase = util.format('%s/app_%s_%s_v%s', prefix, app.id, timestamp, manifest.version);
     var configFilename = filebase + '.json', dataFilename = filebase + '.tar.gz';
 
     settings.getBackupConfig(function (error, backupConfig) {
@@ -293,16 +296,14 @@ function setRestorePoint(appId, lastBackupId, callback) {
     });
 }
 
-function backupApp(app, manifest, tag, callback) {
+function backupApp(app, manifest, prefix, callback) {
     assert.strictEqual(typeof app, 'object');
     assert(manifest && typeof manifest === 'object');
-    assert(tag === null || typeof tag === 'string');
+    assert.strictEqual(typeof prefix, 'string');
     assert.strictEqual(typeof callback, 'function');
 
     var backupFunction;
 
-    if (!tag) tag = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
-
     if (!canBackupApp(app)) {
         if (!app.lastBackupId) {
             debugApp(app, 'backupApp: cannot backup app');
@@ -311,11 +312,11 @@ function backupApp(app, manifest, tag, callback) {
 
         // set the 'creation' date of lastBackup so that the backup persists across time based archival rules
         // s3 does not allow changing creation time, so copying the last backup is easy way out for now
-        backupFunction = copyLastBackup.bind(null, app, manifest, tag);
+        backupFunction = copyLastBackup.bind(null, app, manifest, prefix);
     } else {
         var appConfig = apps.getAppConfig(app);
         appConfig.manifest = manifest;
-        backupFunction = createNewAppBackup.bind(null, app, manifest, tag);
+        backupFunction = createNewAppBackup.bind(null, app, manifest, prefix);
 
         if (!safe.fs.writeFileSync(path.join(paths.DATA_DIR, app.id + '/config.json'), JSON.stringify(appConfig), 'utf8')) {
             return callback(safe.error);
@@ -341,7 +342,7 @@ function backupBoxAndApps(auditSource, callback) {
 
     callback = callback || NOOP_CALLBACK;
 
-    var tag = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
+    var prefix = (new Date()).toISOString().replace(/[T.]/g, '-').replace(/[:Z]/g,'');
 
     eventlog.add(eventlog.ACTION_BACKUP_START, auditSource, { });
 
@@ -356,7 +357,7 @@ function backupBoxAndApps(auditSource, callback) {
         async.mapSeries(allApps, function iterator(app, iteratorCallback) {
             ++processed;
 
-            backupApp(app, app.manifest, tag, function (error, backupId) {
+            backupApp(app, app.manifest, prefix, function (error, backupId) {
                 if (error && error.reason !== BackupsError.BAD_STATE) {
                     debugApp(app, 'Unable to backup', error);
                     return iteratorCallback(error);
@@ -374,7 +375,7 @@ function backupBoxAndApps(auditSource, callback) {
 
             backupIds = backupIds.filter(function (id) { return id !== null; }); // remove apps in bad state that were never backed up
 
-            backupBoxWithAppBackupIds(backupIds, tag, function (error, filename) {
+            backupBoxWithAppBackupIds(backupIds, prefix, function (error, filename) {
                 progress.set(progress.BACKUP, 100, error ? error.message : '');
 
                 eventlog.add(eventlog.ACTION_BACKUP_FINISH, auditSource, { errorMessage: error ? error.message : null, filename: filename });