update date and submodules
diff --git a/include/grpcpp/security/alts_context.h b/include/grpcpp/security/alts_context.h
index 3a68795..606d395 100644
--- a/include/grpcpp/security/alts_context.h
+++ b/include/grpcpp/security/alts_context.h
@@ -1,6 +1,6 @@
/*
*
- * Copyright 2019 gRPC authors.
+ * Copyright 2020 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
diff --git a/src/cpp/common/alts_context.cc b/src/cpp/common/alts_context.cc
index 0a518e6..734af75 100644
--- a/src/cpp/common/alts_context.cc
+++ b/src/cpp/common/alts_context.cc
@@ -1,6 +1,6 @@
/*
*
- * Copyright 2019 gRPC authors.
+ * Copyright 2020 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
diff --git a/src/cpp/common/alts_util.cc b/src/cpp/common/alts_util.cc
index b1dc38d..a8beb1b 100644
--- a/src/cpp/common/alts_util.cc
+++ b/src/cpp/common/alts_util.cc
@@ -1,6 +1,6 @@
/*
*
- * Copyright 2019 gRPC authors.
+ * Copyright 2020 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
diff --git a/test/cpp/common/alts_util_test.cc b/test/cpp/common/alts_util_test.cc
index df56563..dd1d29d 100644
--- a/test/cpp/common/alts_util_test.cc
+++ b/test/cpp/common/alts_util_test.cc
@@ -1,6 +1,6 @@
/*
*
- * Copyright 2019 gRPC authors.
+ * Copyright 2020 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
