diff --git a/mongoext/registry.go b/mongoext/registry.go
new file mode 100644
index 0000000..982102f
--- /dev/null
+++ b/mongoext/registry.go
@@ -0,0 +1,31 @@
+package mongoext
+
+import (
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
+	"gogs.mikescher.com/BlackForestBytes/goext/rfctime"
+	"reflect"
+)
+
+func CreateGoExtBsonRegistry() *bsoncodec.Registry {
+	var primitiveCodecs bson.PrimitiveCodecs
+
+	rb := bsoncodec.NewRegistryBuilder()
+	bsoncodec.DefaultValueEncoders{}.RegisterDefaultEncoders(rb)
+	bsoncodec.DefaultValueDecoders{}.RegisterDefaultDecoders(rb)
+
+	rb.RegisterTypeDecoder(reflect.TypeOf(rfctime.RFC3339Time{}), rfctime.RFC3339Time{})
+
+	primitiveCodecs.RegisterPrimitiveCodecs(rb)
+
+	return rb.Build()
+}
+
+func encodeRFC3339Time(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) {
+
+}
+
+func decodeRFC3339Time(ec bsoncodec.EncodeContext, vr bsonrw.ValueReader, val reflect.Value) {
+
+}
diff --git a/rfctime/rfc3339.go b/rfctime/rfc3339.go
index aea8e4f..d89419b 100644
--- a/rfctime/rfc3339.go
+++ b/rfctime/rfc3339.go
@@ -5,7 +5,10 @@ import (
 	"errors"
 	"fmt"
 	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/bson/bsoncodec"
+	"go.mongodb.org/mongo-driver/bson/bsonrw"
 	"go.mongodb.org/mongo-driver/bson/bsontype"
+	"reflect"
 	"time"
 )
 
@@ -86,6 +89,32 @@ func (t RFC3339Time) MarshalBSONValue() (bsontype.Type, []byte, error) {
 	return bson.MarshalValue(time.Time(t))
 }
 
+func (t RFC3339Time) DecodeValue(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error {
+	if val.Kind() == reflect.Ptr && val.IsNil() {
+		if !val.CanSet() {
+			return errors.New("ValueUnmarshalerDecodeValue")
+		}
+		val.Set(reflect.New(val.Type().Elem()))
+	}
+
+	tp, src, err := bsonrw.Copier{}.CopyValueToBytes(vr)
+	if err != nil {
+		return err
+	}
+
+	if val.Kind() == reflect.Ptr && len(src) == 0 {
+		val.Set(reflect.Zero(val.Type()))
+		return nil
+	}
+
+	err = t.UnmarshalBSONValue(tp, src)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (t RFC3339Time) Serialize() string {
 	return t.Time().Format(t.FormatStr())
 }