diff --git a/fs.go b/fs.go
index bfca0d3fd..7b167e526 100644
--- a/fs.go
+++ b/fs.go
@@ -32,6 +32,9 @@ type Fs interface {
 
 	// Remove the directory (container, bucket) if empty
 	Rmdir() error
+
+	// Precision of the ModTimes in this Fs
+	Precision() time.Duration
 }
 
 // FIXME make f.Debugf...
@@ -168,10 +171,11 @@ func Equal(src, dst FsObject) bool {
 	// Size the same so check the mtime
 	srcModTime := src.ModTime()
 	dstModTime := dst.ModTime()
-	if !dstModTime.Equal(srcModTime) {
-		FsDebug(src, "Modification times differ: %v, %v", srcModTime, dstModTime)
+	dt := dstModTime.Sub(srcModTime)
+	if dt >= *modifyWindow || dt <= -*modifyWindow {
+		FsDebug(src, "Modification times differ by %s: %v, %v", dt, srcModTime, dstModTime)
 	} else {
-		FsDebug(src, "Size and modification time the same")
+		FsDebug(src, "Size and modification time differ by %s (within %s)", dt, *modifyWindow)
 		return true
 	}
 
diff --git a/fs_drive.go b/fs_drive.go
index 8dc080f76..13c8635af 100644
--- a/fs_drive.go
+++ b/fs_drive.go
@@ -1,8 +1,15 @@
 // Drive interface
 package main
 
+// FIXME drive code is leaking goroutines somehow
+
+// FIXME use recursive listing not bound to directory for speed?
+
 // FIXME list containers equivalent should list directories?
 
+// FIXME list directory should list to channel for concurrency not
+// append to array
+
 // FIXME drive times only accurate to 1 ms (3 decimal places)
 
 // FIXME perhaps have a drive setup mode where we ask for all the
@@ -24,8 +31,10 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"mime"
 	"net/http"
 	"os"
+	"path"
 	"regexp"
 	"strings"
 	"sync"
@@ -458,12 +467,18 @@ func (f *FsDrive) Put(in io.Reader, remote string, modTime time.Time, size int64
 		return nil, fmt.Errorf("Couldn't find or make directory: %s", err)
 	}
 
+	// Guess the mime type
+	mimeType := mime.TypeByExtension(path.Ext(remote))
+	if mimeType == "" {
+		mimeType = "application/octet-stream"
+	}
+
 	// Define the metadata for the file we are going to create.
 	info := &drive.File{
 		Title:       leaf,
 		Description: leaf,
 		Parents:     []*drive.ParentReference{{Id: directoryId}},
-		// FIXME set mimeType: 
+		MimeType:    mimeType,
 	}
 
 	// FIXME can't set modified date on initial upload as no
@@ -483,12 +498,13 @@ func (f *FsDrive) Put(in io.Reader, remote string, modTime time.Time, size int64
 	if err != nil {
 		return nil, fmt.Errorf("Upload failed: %s", err)
 	}
+	fs.info = info
 
 	// Set modified date
 	info.ModifiedDate = modTime.Format(time.RFC3339Nano)
 	_, err = f.svc.Files.Update(info.Id, info).SetModifiedDate(true).Do()
 	if err != nil {
-		return nil, fmt.Errorf("Failed to set mtime: %s", err)
+		return fs, fmt.Errorf("Failed to set mtime: %s", err)
 	}
 	return fs, nil
 }
@@ -523,6 +539,11 @@ func (f *FsDrive) Rmdir() error {
 	return nil
 }
 
+// Return the precision
+func (fs *FsDrive) Precision() time.Duration {
+	return time.Millisecond
+}
+
 // Purge deletes all the files and the container
 //
 // Returns an error if it isn't empty
diff --git a/fs_local.go b/fs_local.go
index ba9d8e8b6..33036fd5d 100644
--- a/fs_local.go
+++ b/fs_local.go
@@ -5,16 +5,20 @@ import (
 	"crypto/md5"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 	"path"
 	"path/filepath"
+	"sync"
 	"time"
 )
 
 // FsLocal represents a local filesystem rooted at root
 type FsLocal struct {
-	root string
+	root        string        // The root directory
+	precisionOk sync.Once     // Whether we need to read the precision
+	precision   time.Duration // precision of local filesystem
 }
 
 // FsObjectLocal represents a local filesystem object
@@ -144,6 +148,63 @@ func (f *FsLocal) Rmdir() error {
 	return os.Remove(f.root)
 }
 
+// Return the precision
+func (f *FsLocal) Precision() (precision time.Duration) {
+	f.precisionOk.Do(func() {
+		f.precision = f.readPrecision()
+	})
+	return f.precision
+}
+
+// Read the precision
+func (f *FsLocal) readPrecision() (precision time.Duration) {
+	// Default precision of 1s
+	precision = time.Second
+
+	// Create temporary file and test it
+	fd, err := ioutil.TempFile("", "swiftsync")
+	if err != nil {
+		// If failed return 1s
+		// fmt.Println("Failed to create temp file", err)
+		return time.Second
+	}
+	path := fd.Name()
+	// fmt.Println("Created temp file", path)
+	fd.Close()
+
+	// Delete it on return
+	defer func() {
+		// fmt.Println("Remove temp file")
+		os.Remove(path)
+	}()
+
+	// Find the minimum duration we can detect
+	for duration := time.Duration(1); duration < time.Second; duration *= 10 {
+		// Current time with delta
+		t := time.Unix(time.Now().Unix(), int64(duration))
+		err := Chtimes(path, t, t)
+		if err != nil {
+			// fmt.Println("Failed to Chtimes", err)
+			break
+		}
+
+		// Read the actual time back
+		fi, err := os.Stat(path)
+		if err != nil {
+			// fmt.Println("Failed to Stat", err)
+			break
+		}
+
+		// If it matches - have found the precision
+		// fmt.Println("compare", fi.ModTime(), t)
+		if fi.ModTime() == t {
+			// fmt.Println("Precision detected as", duration)
+			return duration
+		}
+	}
+	return
+}
+
 // ------------------------------------------------------------
 
 // Return the remote path
diff --git a/fs_s3.go b/fs_s3.go
index 8f0586888..c9ef02607 100644
--- a/fs_s3.go
+++ b/fs_s3.go
@@ -244,6 +244,11 @@ func (f *FsS3) Rmdir() error {
 	return f.b.DelBucket()
 }
 
+// Return the precision
+func (fs *FsS3) Precision() time.Duration {
+	return time.Nanosecond
+}
+
 // ------------------------------------------------------------
 
 // Return the remote path
diff --git a/fs_swift.go b/fs_swift.go
index 844694f8f..8db951d36 100644
--- a/fs_swift.go
+++ b/fs_swift.go
@@ -39,6 +39,7 @@ var (
 	authUrl  = flag.String("auth", os.Getenv("ST_AUTH"), "Auth URL for server. Defaults to environment var ST_AUTH.")
 	userName = flag.String("user", os.Getenv("ST_USER"), "User name. Defaults to environment var ST_USER.")
 	apiKey   = flag.String("key", os.Getenv("ST_KEY"), "API key (password). Defaults to environment var ST_KEY.")
+	snet     = flag.Bool("snet", false, "Use internal service network") // FIXME not implemented
 )
 
 // String converts this FsSwift to a string
@@ -200,6 +201,11 @@ func (f *FsSwift) Rmdir() error {
 	return f.c.ContainerDelete(f.container)
 }
 
+// Return the precision
+func (fs *FsSwift) Precision() time.Duration {
+	return time.Nanosecond
+}
+
 // ------------------------------------------------------------
 
 // Return the remote path
diff --git a/notes.txt b/notes.txt
index 44eb1854e..101a37d64 100644
--- a/notes.txt
+++ b/notes.txt
@@ -1,7 +1,6 @@
 Todo
   * Make a test suite which can run on all the given types of fs
   * Copy should use the sync code as it is more efficient at directory listing
-  * Drive needs a modify window of 1ms
   * Factor fses into own packages
   * FIXME: ls without an argument for buckets/containers?
   * FIXME: More -dry-run checks for object transfer
@@ -19,8 +18,8 @@ Todo
   * Check the locking in swift module!
   * Windows paths? Do we need to translate / and \?
   * Make a fs.Errorf and count errors and log them at a different level
-  * add -modify-window flag - fs should keep knowledge of resolution
   * Add max object size to fs metadata - 5GB for swift, infinite for local, ? for s3
+    * tie into -max-size flag
 
 Drive
   * Do we need the secrets or just the code?  If just the code then
@@ -33,11 +32,13 @@ Drive
     * It receives the token back
     * It displays the token to the user to paste in to the code
     * Should be https really
-   
+  * Sometimes get: Failed to copy: Upload failed: googleapi: Error 403: Rate Limit Exceeded
+    * quota is 100.0 requests/second/user
+
 Ideas
   * could do encryption - put IV into metadata?
   * optimise remote copy container to another container using remote
-    copy if local is same as remote
+    copy if local is same as remote - use an optional Copier interface
   * Allow subpaths container:/sub/path
   * look at auth from env in s3 module - add to swift?
   * support
diff --git a/swiftsync.go b/swiftsync.go
index 31c3f439b..dafb2adff 100644
--- a/swiftsync.go
+++ b/swiftsync.go
@@ -19,13 +19,13 @@ import (
 var (
 	// Flags
 	cpuprofile    = flag.String("cpuprofile", "", "Write cpu profile to file")
-	snet          = flag.Bool("snet", false, "Use internal service network") // FIXME not implemented
 	verbose       = flag.Bool("verbose", false, "Print lots more stuff")
 	quiet         = flag.Bool("quiet", false, "Print as little stuff as possible")
 	dry_run       = flag.Bool("dry-run", false, "Do a trial run with no permanent changes")
 	checkers      = flag.Int("checkers", 8, "Number of checkers to run in parallel.")
 	transfers     = flag.Int("transfers", 4, "Number of file transfers to run in parallel.")
 	statsInterval = flag.Duration("stats", time.Minute*1, "Interval to print stats")
+	modifyWindow  = flag.Duration("modify-window", time.Nanosecond, "Max time diff to be considered the same")
 )
 
 // A pair of FsObjects
@@ -566,6 +566,23 @@ func main() {
 		fsrc, fdst = fdst, fsrc
 	}
 
+	// Work out modify window
+	if fsrc != nil {
+		precision := fsrc.Precision()
+		log.Printf("Source precision %s\n", precision)
+		if precision > *modifyWindow {
+			*modifyWindow = precision
+		}
+	}
+	if fdst != nil {
+		precision := fdst.Precision()
+		log.Printf("Destination precision %s\n", precision)
+		if precision > *modifyWindow {
+			*modifyWindow = precision
+		}
+	}
+	log.Printf("Modify window is %s\n", *modifyWindow)
+
 	// Print the stats every statsInterval
 	go func() {
 		ch := time.Tick(*statsInterval)
@@ -579,6 +596,7 @@ func main() {
 	if found.run != nil {
 		found.run(fdst, fsrc)
 		fmt.Println(stats)
+		log.Printf("*** Go routines at exit %d\n", runtime.NumGoroutine())
 		if stats.errors > 0 {
 			os.Exit(1)
 		}