diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseType.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseType.java
index 7303e1f85..a81a27e60 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseType.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseType.java
@@ -48,11 +48,11 @@ public enum BaseType {
         return identifier;
     }
 
-    public Object decode(ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(ByteBuffer byteBuffer, double scale, int offset) {
         return baseTypeInterface.decode(byteBuffer, scale, offset);
     }
 
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         baseTypeInterface.encode(byteBuffer, o, scale, offset);
     }
 
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeByte.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeByte.java
index 4ada1b3ce..c70f3c821 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeByte.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeByte.java
@@ -28,22 +28,22 @@ public class BaseTypeByte implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(final ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(final ByteBuffer byteBuffer, double scale, int offset) {
         int b = unsigned ? Byte.toUnsignedInt(byteBuffer.get()) : byteBuffer.get();
         if (b < min || b > max)
             return null;
         if (b == invalid)
             return null;
-        return (b + offset) / scale;
+        return (int) (Math.round(b / scale) - offset);
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        int i = ((Number) o).intValue() * scale - offset;
+        int i = (int) ((((Number) o).intValue() + offset) * scale);
         if (i < min || i > max) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeDouble.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeDouble.java
index e517c8410..8dfbc301a 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeDouble.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeDouble.java
@@ -19,23 +19,23 @@ public class BaseTypeDouble implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(final ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(final ByteBuffer byteBuffer, double scale, int offset) {
         double d = byteBuffer.getDouble();
         if (d < min || d > max) {
             return null;
         }
         if (Double.isNaN(d) || d == invalid)
             return null;
-        return (d + offset) / scale;
+        return (d / scale) - offset;
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        double d = ((Number) o).doubleValue() * scale - offset;
+        double d = (((Number) o).doubleValue() + offset) * scale;
         if (d < min || d > max) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeFloat.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeFloat.java
index 41f713cd9..2df247aec 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeFloat.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeFloat.java
@@ -19,23 +19,23 @@ public class BaseTypeFloat implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(ByteBuffer byteBuffer, double scale, int offset) {
         float f = byteBuffer.getFloat();
         if (f < min || f > max) {
             return null;
         }
         if (Float.isNaN(f) || f == invalid)
             return null;
-        return (f + offset) / scale;
+        return (float) (f / scale) - offset;
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        float f = ((Number) o).floatValue() * scale - offset;
+        float f = (float) ((((Number) o).floatValue() + offset) * scale);
         if (f < min || f > max) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInt.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInt.java
index b463062f2..4f48cd776 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInt.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInt.java
@@ -26,22 +26,22 @@ public class BaseTypeInt implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(final ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(final ByteBuffer byteBuffer, double scale, int offset) {
         long i = unsigned ? Integer.toUnsignedLong(byteBuffer.getInt()) : byteBuffer.getInt();
         if (i < min || i > max)
             return null;
         if (i == invalid)
             return null;
-        return ((i + offset) / scale);
+        return (Math.round(i / scale) - offset);
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        long l = ((Number) o).longValue() * scale - offset;
+        long l = (long) ((((Number) o).longValue() + offset) * scale);
         if (l < min || l > max) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInterface.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInterface.java
index 3784c0ac8..60fd8e120 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInterface.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeInterface.java
@@ -5,9 +5,9 @@ import java.nio.ByteBuffer;
 public interface BaseTypeInterface {
     int getByteSize();
 
-    Object decode(ByteBuffer byteBuffer, int scale, int offset);
+    Object decode(ByteBuffer byteBuffer, double scale, int offset);
 
-    void encode(ByteBuffer byteBuffer, Object o, int scale, int offset);
+    void encode(ByteBuffer byteBuffer, Object o, double scale, int offset);
 
     void invalidate(ByteBuffer byteBuffer);
 }
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeLong.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeLong.java
index 74af9461a..479fb5534 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeLong.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeLong.java
@@ -1,5 +1,6 @@
 package nodomain.freeyourgadget.gadgetbridge.service.devices.garmin.fit.baseTypes;
 
+import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.nio.ByteBuffer;
 
@@ -27,22 +28,22 @@ public class BaseTypeLong implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(ByteBuffer byteBuffer, double scale, int offset) {
         BigInteger i = unsigned ? BigInteger.valueOf(byteBuffer.getLong() & 0xFFFFFFFFFFFFFFFFL) : BigInteger.valueOf(byteBuffer.getLong());
         if (!unsigned && (i.compareTo(min) < 0 || i.compareTo(max) > 0))
             return null;
         if (i.compareTo(BigInteger.valueOf(invalid)) == 0)
             return null;
-        return (i.longValue() + offset) / scale;
+        return new BigDecimal(i).divide(BigDecimal.valueOf(scale)).subtract(BigDecimal.valueOf(offset)).toBigInteger().longValue();
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        BigInteger i = BigInteger.valueOf(((Number) o).longValue() * scale - offset);
+        BigInteger i = new BigDecimal(((Number) o).longValue()).multiply(BigDecimal.valueOf(scale)).add(BigDecimal.valueOf(offset)).toBigInteger();
         if (!unsigned && (i.compareTo(min) < 0 || i.compareTo(max) > 0)) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeShort.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeShort.java
index ade9d357d..0a76c6efe 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeShort.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/baseTypes/BaseTypeShort.java
@@ -26,22 +26,22 @@ public class BaseTypeShort implements BaseTypeInterface {
     }
 
     @Override
-    public Object decode(final ByteBuffer byteBuffer, int scale, int offset) {
+    public Object decode(final ByteBuffer byteBuffer, double scale, int offset) {
         int s = unsigned ? Short.toUnsignedInt(byteBuffer.getShort()) : byteBuffer.getShort();
         if (s < min || s > max)
             return null;
         if (s == invalid)
             return null;
-        return (s + offset) / scale;
+        return (int) Math.round(s / scale) - offset;
     }
 
     @Override
-    public void encode(ByteBuffer byteBuffer, Object o, int scale, int offset) {
+    public void encode(ByteBuffer byteBuffer, Object o, double scale, int offset) {
         if (null == o) {
             invalidate(byteBuffer);
             return;
         }
-        int i = ((Number) o).intValue() * scale - offset;
+        int i = (int) ((((Number) o).intValue() + offset) * scale);
         if (i < min || i > max) {
             invalidate(byteBuffer);
             return;
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/fieldDefinitions/FieldDefinitionTimestamp.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/fieldDefinitions/FieldDefinitionTimestamp.java
index fed1ba665..c45b05173 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/fieldDefinitions/FieldDefinitionTimestamp.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/garmin/fit/fieldDefinitions/FieldDefinitionTimestamp.java
@@ -7,7 +7,7 @@ import static nodomain.freeyourgadget.gadgetbridge.service.devices.garmin.Garmin
 
 public class FieldDefinitionTimestamp extends FieldDefinition {
     public FieldDefinitionTimestamp(int localNumber, int size, BaseType baseType, String name) {
-        super(localNumber, size, baseType, name, 1, GARMIN_TIME_EPOCH);
+        super(localNumber, size, baseType, name, 1, -GARMIN_TIME_EPOCH);
     }
 
 //    @Override