diff --git a/app/build.gradle b/app/build.gradle
index 770827ff..f74714b0 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -27,4 +27,5 @@ dependencies {
     compile 'com.github.tony19:logback-android-classic:1.1.1-3'
     compile 'org.slf4j:slf4j-api:1.7.7'
     compile 'com.github.PhilJay:MPAndroidChart:2.1.0'
+    compile 'com.github.pfichtner:durationformatter:0.1.1'
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GB.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GB.java
index 131383df..8eac8707 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GB.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GB.java
@@ -14,6 +14,8 @@ import android.os.Looper;
 import android.support.v4.app.NotificationCompat;
 import android.widget.Toast;
 
+import com.github.pfichtner.durationformatter.DurationFormatter;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -22,6 +24,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
+import java.util.concurrent.TimeUnit;
 
 import nodomain.freeyourgadget.gadgetbridge.deviceevents.GBDeviceEventScreenshot;
 import nodomain.freeyourgadget.gadgetbridge.externalevents.K9Receiver;
@@ -248,4 +251,14 @@ public class GB {
                 break;
         }
     }
+
+    public static String formatDurationHoursMinutes(long duration, TimeUnit unit) {
+        DurationFormatter df = DurationFormatter.Builder.SYMBOLS
+                .maximum(TimeUnit.DAYS)
+                .minimum(TimeUnit.MINUTES)
+                .suppressZeros(DurationFormatter.SuppressZeros.LEADING)
+                .maximumAmountOfUnitsToShow(2)
+                .build();
+        return df.format(duration, unit);
+    }
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractChartFragment.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractChartFragment.java
index 351fa573..789e5535 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractChartFragment.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/AbstractChartFragment.java
@@ -24,6 +24,7 @@ import nodomain.freeyourgadget.gadgetbridge.GBActivitySample;
 import nodomain.freeyourgadget.gadgetbridge.GBApplication;
 import nodomain.freeyourgadget.gadgetbridge.GBDevice;
 import nodomain.freeyourgadget.gadgetbridge.R;
+import nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind;
 import nodomain.freeyourgadget.gadgetbridge.charts.SleepUtils;
 
 public abstract class AbstractChartFragment extends Fragment {
@@ -54,6 +55,18 @@ public abstract class AbstractChartFragment extends Fragment {
     protected static final int CHART_TEXT_COLOR = Color.WHITE;
     protected static final int LEGEND_TEXT_COLOR = Color.WHITE;
 
+    protected Integer getColorFor(int activityKind) {
+        switch (activityKind) {
+            case nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind.TYPE_DEEP_SLEEP:
+                return akDeepSleep.color;
+            case nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind.TYPE_LIGHT_SLEEP:
+                return akLightSleep.color;
+            case nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind.TYPE_ACTIVITY:
+                    return akActivity.color;
+        }
+        return akActivity.color;
+    }
+
     protected byte getProvider(GBDevice device) {
         byte provider = -1;
         switch (device.getType()) {
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/SleepChartFragment.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/SleepChartFragment.java
index 1ef20c9b..643f880a 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/SleepChartFragment.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/SleepChartFragment.java
@@ -18,14 +18,18 @@ import com.github.mikephil.charting.components.YAxis;
 import com.github.mikephil.charting.data.Entry;
 import com.github.mikephil.charting.data.PieData;
 import com.github.mikephil.charting.data.PieDataSet;
+import com.github.mikephil.charting.utils.ValueFormatter;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.text.NumberFormat;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 import nodomain.freeyourgadget.gadgetbridge.ControlCenter;
+import nodomain.freeyourgadget.gadgetbridge.GB;
 import nodomain.freeyourgadget.gadgetbridge.GBActivitySample;
 import nodomain.freeyourgadget.gadgetbridge.GBDevice;
 import nodomain.freeyourgadget.gadgetbridge.R;
@@ -77,18 +81,25 @@ public class SleepChartFragment extends AbstractChartFragment {
     private void refreshSleepAmounts(GBDevice mGBDevice, PieChart pieChart, List<GBActivitySample> samples) {
         ActivityAnalysis analysis = new ActivityAnalysis();
         ActivityAmounts amounts = analysis.calculateActivityAmounts(samples);
-        float hoursOfSleep = amounts.getTotalSeconds() / (float) (60 * 60);
-        pieChart.setCenterText((int)hoursOfSleep + "h"); // FIXME
+        String totalSleep = GB.formatDurationHoursMinutes(amounts.getTotalSeconds(), TimeUnit.SECONDS);
+        pieChart.setCenterText(totalSleep);
         PieData data = new PieData();
         List<Entry> entries = new ArrayList<>();
         List<Integer> colors = new ArrayList<>();
         int index = 0;
         for (ActivityAmount amount : amounts.getAmounts()) {
+            long value = amount.getTotalSeconds();
             entries.add(new Entry(amount.getTotalSeconds(), index++));
             colors.add(getColorFor(amount.getActivityKind()));
             data.addXValue(amount.getName(getActivity()));
         }
-        PieDataSet set = new PieDataSet(entries, "Sleep comparison");
+        PieDataSet set = new PieDataSet(entries, "");
+        set.setValueFormatter(new ValueFormatter() {
+            @Override
+            public String getFormattedValue(float value) {
+                return GB.formatDurationHoursMinutes((long)value, TimeUnit.SECONDS);
+            }
+        });
         set.setColors(colors);
         data.setDataSet(set);
         pieChart.setData(data);
@@ -98,16 +109,6 @@ public class SleepChartFragment extends AbstractChartFragment {
         pieChart.invalidate();
     }
 
-    private Integer getColorFor(int activityKind) {
-        switch (activityKind) {
-            case nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind.TYPE_DEEP_SLEEP:
-                return akDeepSleep.color;
-            case nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind.TYPE_LIGHT_SLEEP:
-                return akLightSleep.color;
-        }
-        return akActivity.color;
-    }
-
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
@@ -138,6 +139,9 @@ public class SleepChartFragment extends AbstractChartFragment {
     private void setupSleepAmountChart() {
         mSleepAmountChart.setBackgroundColor(BACKGROUND_COLOR);
         mSleepAmountChart.setDescriptionColor(DESCRIPTION_COLOR);
+        mSleepAmountChart.setDescription("");
+        mSleepAmountChart.setNoDataTextDescription("");
+        mSleepAmountChart.setNoDataText("");
     }
 
     @Override
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
index 78a22f73..20dcbef9 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/miband/MiBandSupport.java
@@ -18,6 +18,7 @@ import java.util.Arrays;
 import java.util.Calendar;
 import java.util.GregorianCalendar;
 import java.util.UUID;
+import java.util.concurrent.TimeUnit;
 
 import nodomain.freeyourgadget.gadgetbridge.GB;
 import nodomain.freeyourgadget.gadgetbridge.GBActivitySample;
@@ -652,7 +653,11 @@ public class MiBandSupport extends AbstractBTLEDeviceSupport {
             // after dataUntilNextHeader bytes we will get a new packet of 11 bytes that should be parsed
             // as we just did
 
-            GB.toast(getContext().getString(R.string.user_feedback_miband_activity_data_transfer,(dataUntilNextHeader / 3), DateFormat.getDateTimeInstance().format(timestamp.getTime())), Toast.LENGTH_SHORT, GB.INFO);
+            if (dataUntilNextHeader != 0) {
+                GB.toast(getContext().getString(R.string.user_feedback_miband_activity_data_transfer,
+                        GB.formatDurationHoursMinutes(dataUntilNextHeader / 3, TimeUnit.MINUTES),
+                        DateFormat.getDateTimeInstance().format(timestamp.getTime())), Toast.LENGTH_LONG, GB.INFO);
+            }
             LOG.info("total data to read: " + totalDataToRead + " len: " + (totalDataToRead / 3) + " minute(s)");
             LOG.info("data to read until next header: " + dataUntilNextHeader + " len: " + (dataUntilNextHeader / 3) + " minute(s)");
             LOG.info("TIMESTAMP: " + DateFormat.getDateTimeInstance().format(timestamp.getTime()).toString() + " magic byte: " + dataUntilNextHeader);
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 79ffba3f..950f89e0 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -152,5 +152,5 @@
     <string name="user_feedback_miband_set_alarms_failed">There was an error setting the alarms, please try again!</string>
     <string name="user_feedback_miband_set_alarms_ok">Alarms sent to device!</string>
     <string name="chart_no_data_synchronize">No data. Synchronize device?</string>
-    <string name="user_feedback_miband_activity_data_transfer">About to transfer %1$s minute(s) of data starting from %2$s</string>
+    <string name="user_feedback_miband_activity_data_transfer">About to transfer %1$s of data starting from %2$s</string>
 </resources>