diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index c0dedf4aff2b0acee095e967e8d699a9f0c2e3c1..ee089e3dd210d4682406d90ddfd33559709c0a98 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -31,6 +31,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-453 - GPU search error when nprobe set more than 1024
 - MS-510 - unittest out of memory and crashed
 - MS-119 - The problem of combining the log files
+- MS-121 - The problem that user can't change the time zone
 
 ## Improvement
 - MS-327 - Clean code for milvus
diff --git a/cpp/conf/server_config.template b/cpp/conf/server_config.template
index ecfcd25f784fd5c7a6dd41344c55819099824038..121d15d1d84bc4ab8a3da8bc1fdc991d9ce45d89 100644
--- a/cpp/conf/server_config.template
+++ b/cpp/conf/server_config.template
@@ -3,6 +3,7 @@ server_config:
   port: 19530                 # the port milvus listen to, default: 19530, range: 1025 ~ 65534
   gpu_index: 0                # the gpu milvus use, default: 0, range: 0 ~ gpu number - 1
   mode: single                # milvus deployment type: single, cluster, read_only
+  time_zone: UTC+8            # Use the UTC-x or UTC+x to specify a time zone. eg. UTC+8 for China Standard Time
 
 db_config:
   db_path: @MILVUS_DB_PATH@             # milvus data storage path
diff --git a/cpp/src/main.cpp b/cpp/src/main.cpp
index ec536c2ee2e0a20dc3c67602466202a38681699b..8590da27be24be5a6de8427d59a643b0dea3eb44 100644
--- a/cpp/src/main.cpp
+++ b/cpp/src/main.cpp
@@ -16,7 +16,6 @@
 
 #include "utils/SignalUtil.h"
 #include "utils/CommonUtil.h"
-#include "utils/LogUtil.h"
 
 INITIALIZE_EASYLOGGINGPP
 
@@ -98,10 +97,8 @@ main(int argc, char *argv[]) {
         }
     }
 
-    zilliz::milvus::server::InitLog(log_config_file);
-
     server::Server* server_ptr = server::Server::Instance();
-    server_ptr->Init(start_daemonized, pid_filename, config_filename);
+    server_ptr->Init(start_daemonized, pid_filename, config_filename, log_config_file);
     return server_ptr->Start();
 }
 
diff --git a/cpp/src/server/Server.cpp b/cpp/src/server/Server.cpp
index 449c2d422df8edfd27a3a7d0421968341a42928a..4a456ff726e9e857ab03728b53c5c0d658033183 100644
--- a/cpp/src/server/Server.cpp
+++ b/cpp/src/server/Server.cpp
@@ -7,6 +7,7 @@
 #include "Server.h"
 #include "server/grpc_impl/GrpcMilvusServer.h"
 #include "utils/Log.h"
+#include "utils/LogUtil.h"
 #include "utils/SignalUtil.h"
 #include "utils/TimeRecorder.h"
 #include "metrics/Metrics.h"
@@ -24,11 +25,12 @@
 #include "metrics/Metrics.h"
 #include "DBWrapper.h"
 
+
 namespace zilliz {
 namespace milvus {
 namespace server {
 
-Server*
+Server *
 Server::Instance() {
     static Server server;
     return &server;
@@ -42,10 +44,14 @@ Server::~Server() {
 }
 
 void
-Server::Init(int64_t daemonized, const std::string& pid_filename, const std::string& config_filename) {
+Server::Init(int64_t daemonized,
+             const std::string &pid_filename,
+             const std::string &config_filename,
+             const std::string &log_config_file) {
     daemonized_ = daemonized;
     pid_filename_ = pid_filename;
     config_filename_ = config_filename;
+    log_config_file_ = log_config_file;
 }
 
 void
@@ -54,7 +60,7 @@ Server::Daemonize() {
         return;
     }
 
-    SERVER_LOG_INFO << "Milvus server run in daemonize mode";
+    std::cout << "Milvus server run in daemonize mode";
 
 //    std::string log_path(GetLogDirFullPath());
 //    log_path += "zdb_server.(INFO/WARNNING/ERROR/CRITICAL)";
@@ -101,7 +107,7 @@ Server::Daemonize() {
 
     // Change the working directory to root
     int ret = chdir("/");
-    if(ret != 0){
+    if (ret != 0) {
         return;
     }
 
@@ -110,7 +116,7 @@ Server::Daemonize() {
         close(fd);
     }
 
-    SERVER_LOG_INFO << "Redirect stdin/stdout/stderr to /dev/null";
+    std::cout << "Redirect stdin/stdout/stderr to /dev/null";
 
     // Redirect stdin/stdout/stderr to /dev/null
     stdin = fopen("/dev/null", "r");
@@ -120,17 +126,17 @@ Server::Daemonize() {
     if (!pid_filename_.empty()) {
         pid_fd = open(pid_filename_.c_str(), O_RDWR | O_CREAT, 0640);
         if (pid_fd < 0) {
-            SERVER_LOG_INFO << "Can't open filename: " + pid_filename_ + ", Error: " + strerror(errno);
+            std::cout << "Can't open filename: " + pid_filename_ + ", Error: " + strerror(errno);
             exit(EXIT_FAILURE);
         }
         if (lockf(pid_fd, F_TLOCK, 0) < 0) {
-            SERVER_LOG_INFO << "Can't lock filename: " + pid_filename_ + ", Error: " + strerror(errno);
+            std::cout << "Can't lock filename: " + pid_filename_ + ", Error: " + strerror(errno);
             exit(EXIT_FAILURE);
         }
 
         std::string pid_file_context = std::to_string(getpid());
         ssize_t res = write(pid_fd, pid_file_context.c_str(), pid_file_context.size());
-        if(res != 0){
+        if (res != 0) {
             return;
         }
     }
@@ -146,7 +152,7 @@ Server::Start() {
     do {
         try {
             // Read config file
-            if(LoadConfig() != SERVER_SUCCESS) {
+            if (LoadConfig() != SERVER_SUCCESS) {
                 return 1;
             }
 
@@ -154,6 +160,27 @@ Server::Start() {
             ServerConfig &config = ServerConfig::GetInstance();
             ConfigNode server_config = config.GetConfig(CONFIG_SERVER);
 
+            std::string time_zone = server_config.GetValue(CONFIG_TIME_ZONE, "UTC+8");
+            if (time_zone.length() == 3) {
+                time_zone = "CUT";
+            } else {
+                int time_bias = std::stoi(time_zone.substr(3, std::string::npos));
+                if (time_bias == 0)
+                    time_zone = "CUT";
+                else if (time_bias > 0) {
+                    time_zone = "CUT" + std::to_string(-time_bias);
+                } else {
+                    time_zone = "CUT+" + std::to_string(-time_bias);
+                }
+            }
+
+            if (setenv("TZ", time_zone.c_str(), 1) != 0) {
+                return -1;
+            }
+            tzset();
+
+            InitLog(log_config_file_);
+
             // Handle Signal
             signal(SIGINT, SignalUtil::HandleSignal);
             signal(SIGHUP, SignalUtil::HandleSignal);
@@ -164,12 +191,12 @@ Server::Start() {
             std::cout << "Milvus server start successfully." << std::endl;
             StartService();
 
-        } catch(std::exception& ex){
-            SERVER_LOG_ERROR << "Milvus server encounter exception: " << std::string(ex.what())
-                             << "Is another server instance running?";
+        } catch (std::exception &ex) {
+            std::cerr << "Milvus server encounter exception: " << std::string(ex.what())
+                      << "Is another server instance running?";
             break;
         }
-    } while(false);
+    } while (false);
 
     Stop();
     return 0;
@@ -182,12 +209,12 @@ Server::Stop() {
     // Unlock and close lockfile
     if (pid_fd != -1) {
         int ret = lockf(pid_fd, F_ULOCK, 0);
-        if(ret != 0){
+        if (ret != 0) {
             std::cout << "Can't lock file: " << strerror(errno) << std::endl;
             exit(0);
         }
         ret = close(pid_fd);
-        if(ret != 0){
+        if (ret != 0) {
             std::cout << "Can't close file: " << strerror(errno) << std::endl;
             exit(0);
         }
@@ -196,7 +223,7 @@ Server::Stop() {
     // Try to delete lockfile
     if (!pid_filename_.empty()) {
         int ret = unlink(pid_filename_.c_str());
-        if(ret != 0){
+        if (ret != 0) {
             std::cout << "Can't unlink file: " << strerror(errno) << std::endl;
             exit(0);
         }
@@ -214,7 +241,7 @@ ErrorCode
 Server::LoadConfig() {
     ServerConfig::GetInstance().LoadConfigFile(config_filename_);
     ErrorCode err = ServerConfig::GetInstance().ValidateConfig();
-    if(err != SERVER_SUCCESS){
+    if (err != SERVER_SUCCESS) {
         exit(0);
     }
 
diff --git a/cpp/src/server/Server.h b/cpp/src/server/Server.h
index c54f90a1980d2cb735f97f376f2b8dfc2ba9a8cd..c5ea076fb95bd73fae0f3222abef51bddf90a291 100644
--- a/cpp/src/server/Server.h
+++ b/cpp/src/server/Server.h
@@ -18,7 +18,7 @@ class Server {
    public:
     static Server* Instance();
 
-    void Init(int64_t daemonized, const std::string& pid_filename, const std::string& config_filename);
+    void Init(int64_t daemonized, const std::string& pid_filename, const std::string& config_filename, const std::string &log_config_file);
     int Start();
     void Stop();
 
@@ -40,6 +40,7 @@ class Server {
     int pid_fd = -1;
     std::string pid_filename_;
     std::string config_filename_;
+    std::string log_config_file_;
 };  // Server
 
 }   // server
diff --git a/cpp/src/server/ServerConfig.cpp b/cpp/src/server/ServerConfig.cpp
index c506b318919a6f90b6a4018bed56df006598a30d..1e430583662ad985c97b0697949bdc8acac183b5 100644
--- a/cpp/src/server/ServerConfig.cpp
+++ b/cpp/src/server/ServerConfig.cpp
@@ -15,23 +15,24 @@
 #include "utils/CommonUtil.h"
 #include "utils/ValidationUtil.h"
 
+
 namespace zilliz {
 namespace milvus {
 namespace server {
 
-constexpr uint64_t MB = 1024*1024;
-constexpr uint64_t GB = MB*1024;
+constexpr uint64_t MB = 1024 * 1024;
+constexpr uint64_t GB = MB * 1024;
 
-ServerConfig&
+ServerConfig &
 ServerConfig::GetInstance() {
     static ServerConfig config;
     return config;
 }
 
 ErrorCode
-ServerConfig::LoadConfigFile(const std::string& config_filename) {
+ServerConfig::LoadConfigFile(const std::string &config_filename) {
     std::string filename = config_filename;
-    if(filename.empty()){
+    if (filename.empty()) {
         std::cout << "ERROR: a config file is required" << std::endl;
         exit(1);//directly exit program if config file not specified
     }
@@ -43,14 +44,14 @@ ServerConfig::LoadConfigFile(const std::string& config_filename) {
     }
 
     try {
-        ConfigMgr* mgr = const_cast<ConfigMgr*>(ConfigMgr::GetInstance());
+        ConfigMgr *mgr = const_cast<ConfigMgr *>(ConfigMgr::GetInstance());
         ErrorCode err = mgr->LoadConfigFile(filename);
-        if(err != 0) {
+        if (err != 0) {
             std::cout << "Server failed to load config file" << std::endl;
             exit(1);//directly exit program if the config file is illegal
         }
     }
-    catch (YAML::Exception& e) {
+    catch (YAML::Exception &e) {
         std::cout << "Server failed to load config file: " << std::endl;
         return SERVER_UNEXPECTED_ERROR;
     }
@@ -104,8 +105,7 @@ ServerConfig::CheckServerConfig() {
     if (ValidationUtil::ValidateStringIsNumber(port_str) != SERVER_SUCCESS) {
         std::cerr << "Error: port " << port_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
+    } else {
         int32_t port = std::stol(port_str);
         if (port < 1025 | port > 65534) {
             std::cerr << "Error: port " << port_str << " out of range [1025, 65534]" << std::endl;
@@ -117,10 +117,9 @@ ServerConfig::CheckServerConfig() {
     if (ValidationUtil::ValidateStringIsNumber(gpu_index_str) != SERVER_SUCCESS) {
         std::cerr << "Error: gpu_index " << gpu_index_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
+    } else {
         int32_t gpu_index = std::stol(gpu_index_str);
-        if(ValidationUtil::ValidateGpuIndex(gpu_index) != SERVER_SUCCESS) {
+        if (ValidationUtil::ValidateGpuIndex(gpu_index) != SERVER_SUCCESS) {
             std::cerr << "Error: invalid gpu_index " << gpu_index_str << std::endl;
             okay = false;
         }
@@ -132,6 +131,25 @@ ServerConfig::CheckServerConfig() {
         okay = false;
     }
 
+    std::string time_zone = server_config.GetValue(CONFIG_TIME_ZONE, "UTC+8");
+    int flag = 0;
+    if(time_zone.length() < 3)
+        flag = 1;
+    else if(time_zone.substr(0, 3) != "UTC")
+        flag = 1;
+    else if(time_zone.length() > 3){
+        try {
+            stoi(time_zone.substr(3, std::string::npos));
+        }
+        catch (std::invalid_argument &) {
+            flag = 1;
+        }
+    }
+    if(flag == 1){
+        std::cerr << "ERROR: time_zone " << time_zone << " is not in a right format" << std::endl;
+        okay = false;
+    }
+
     return (okay ? SERVER_SUCCESS : SERVER_INVALID_ARGUMENT);
 }
 
@@ -190,13 +208,12 @@ ServerConfig::CheckDBConfig() {
     if (ValidationUtil::ValidateStringIsNumber(insert_buffer_size_str) != SERVER_SUCCESS) {
         std::cerr << "Error: insert_buffer_size " << insert_buffer_size_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
-        uint64_t insert_buffer_size = (uint64_t)std::stol(insert_buffer_size_str);
+    } else {
+        uint64_t insert_buffer_size = (uint64_t) std::stol(insert_buffer_size_str);
         insert_buffer_size *= GB;
         unsigned long total_mem = 0, free_mem = 0;
         CommonUtil::GetSystemMemInfo(total_mem, free_mem);
-        if(insert_buffer_size >= total_mem) {
+        if (insert_buffer_size >= total_mem) {
             std::cerr << "Error: insert_buffer_size exceed system memory" << std::endl;
             okay = false;
         }
@@ -254,21 +271,19 @@ ServerConfig::CheckCacheConfig() {
     if (ValidationUtil::ValidateStringIsNumber(cpu_cache_capacity_str) != SERVER_SUCCESS) {
         std::cerr << "Error: cpu_cache_capacity " << cpu_cache_capacity_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
-        uint64_t cpu_cache_capacity = (uint64_t)std::stol(cpu_cache_capacity_str);
+    } else {
+        uint64_t cpu_cache_capacity = (uint64_t) std::stol(cpu_cache_capacity_str);
         cpu_cache_capacity *= GB;
         unsigned long total_mem = 0, free_mem = 0;
         CommonUtil::GetSystemMemInfo(total_mem, free_mem);
         if (cpu_cache_capacity >= total_mem) {
             std::cerr << "Error: cpu_cache_capacity exceed system memory" << std::endl;
             okay = false;
-        }
-        else if(cpu_cache_capacity > (double)total_mem*0.9) {
+        } else if (cpu_cache_capacity > (double) total_mem * 0.9) {
             std::cerr << "Warning: cpu_cache_capacity value is too aggressive" << std::endl;
         }
 
-        uint64_t insert_buffer_size = (uint64_t)GetConfig(CONFIG_DB).GetInt32Value(CONFIG_DB_INSERT_BUFFER_SIZE, 4);
+        uint64_t insert_buffer_size = (uint64_t) GetConfig(CONFIG_DB).GetInt32Value(CONFIG_DB_INSERT_BUFFER_SIZE, 4);
         insert_buffer_size *= GB;
         if (insert_buffer_size + cpu_cache_capacity >= total_mem) {
             std::cerr << "Error: sum of cpu_cache_capacity and insert_buffer_size exceed system memory" << std::endl;
@@ -281,8 +296,7 @@ ServerConfig::CheckCacheConfig() {
     if (ValidationUtil::ValidateStringIsDouble(cpu_cache_free_percent_str, cpu_cache_free_percent) != SERVER_SUCCESS) {
         std::cerr << "Error: cpu_cache_free_percent " << cpu_cache_free_percent_str << " is not a double" << std::endl;
         okay = false;
-    }
-    else if (cpu_cache_free_percent < std::numeric_limits<double>::epsilon() || cpu_cache_free_percent > 1.0) {
+    } else if (cpu_cache_free_percent < std::numeric_limits<double>::epsilon() || cpu_cache_free_percent > 1.0) {
         std::cerr << "Error: invalid cpu_cache_free_percent " << cpu_cache_free_percent_str << std::endl;
         okay = false;
     }
@@ -297,22 +311,19 @@ ServerConfig::CheckCacheConfig() {
     if (ValidationUtil::ValidateStringIsNumber(gpu_cache_capacity_str) != SERVER_SUCCESS) {
         std::cerr << "Error: gpu_cache_capacity " << gpu_cache_capacity_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
-        uint64_t gpu_cache_capacity = (uint64_t)std::stol(gpu_cache_capacity_str);
+    } else {
+        uint64_t gpu_cache_capacity = (uint64_t) std::stol(gpu_cache_capacity_str);
         gpu_cache_capacity *= GB;
         int gpu_index = GetConfig(CONFIG_SERVER).GetInt32Value(CONFIG_GPU_INDEX, 0);
         size_t gpu_memory;
         if (ValidationUtil::GetGpuMemory(gpu_index, gpu_memory) != SERVER_SUCCESS) {
             std::cerr << "Error: could not get gpu memory for device " << gpu_index << std::endl;
             okay = false;
-        }
-        else if (gpu_cache_capacity >= gpu_memory) {
+        } else if (gpu_cache_capacity >= gpu_memory) {
             std::cerr << "Error: gpu_cache_capacity " << gpu_cache_capacity
                       << " exceed total gpu memory " << gpu_memory << std::endl;
             okay = false;
-        }
-        else if(gpu_cache_capacity > (double)gpu_memory*0.9) {
+        } else if (gpu_cache_capacity > (double) gpu_memory * 0.9) {
             std::cerr << "Warning: gpu_cache_capacity value is too aggressive" << std::endl;
         }
     }
@@ -322,8 +333,7 @@ ServerConfig::CheckCacheConfig() {
     if (ValidationUtil::ValidateStringIsDouble(gpu_cache_free_percent_str, gpu_cache_free_percent) != SERVER_SUCCESS) {
         std::cerr << "Error: gpu_cache_free_percent " << gpu_cache_free_percent_str << " is not a double" << std::endl;
         okay = false;
-    }
-    else if (gpu_cache_free_percent < std::numeric_limits<double>::epsilon() || gpu_cache_free_percent > 1.0) {
+    } else if (gpu_cache_free_percent < std::numeric_limits<double>::epsilon() || gpu_cache_free_percent > 1.0) {
         std::cerr << "Error: invalid gpu_cache_free_percent " << gpu_cache_free_percent << std::endl;
         okay = false;
     }
@@ -334,8 +344,7 @@ ServerConfig::CheckCacheConfig() {
         if (ValidationUtil::ValidateStringIsNumber(gpu_id) != SERVER_SUCCESS) {
             std::cerr << "Error: gpu_id " << gpu_id << " is not a number" << std::endl;
             okay = false;
-        }
-        else if (ValidationUtil::ValidateGpuIndex(std::stol(gpu_id)) != SERVER_SUCCESS) {
+        } else if (ValidationUtil::ValidateGpuIndex(std::stol(gpu_id)) != SERVER_SUCCESS) {
             std::cerr << "Error: gpu_id " << gpu_id << " is valid" << std::endl;
             okay = false;
         }
@@ -364,12 +373,12 @@ ServerConfig::CheckEngineConfig() {
     if (ValidationUtil::ValidateStringIsNumber(omp_thread_num_str) != SERVER_SUCCESS) {
         std::cerr << "Error: omp_thread_num " << omp_thread_num_str << " is not a number" << std::endl;
         okay = false;
-    }
-    else {
+    } else {
         int32_t omp_thread = std::stol(omp_thread_num_str);
         uint32_t sys_thread_cnt = 8;
-        if(omp_thread > CommonUtil::GetSystemAvailableThreads(sys_thread_cnt)) {
-            std::cerr << "Error: omp_thread_num " << omp_thread_num_str << " > system available thread " << sys_thread_cnt << std::endl;
+        if (omp_thread > CommonUtil::GetSystemAvailableThreads(sys_thread_cnt)) {
+            std::cerr << "Error: omp_thread_num " << omp_thread_num_str << " > system available thread "
+                      << sys_thread_cnt << std::endl;
             okay = false;
         }
     }
@@ -446,14 +455,13 @@ ServerConfig::CheckResourceConfig() {
         resource_list.emplace(resource.first);
         auto &resource_conf = resource.second;
         auto type = resource_conf.GetValue(CONFIG_RESOURCE_TYPE);
-        
+
         std::string device_id_str = resource_conf.GetValue(CONFIG_RESOURCE_DEVICE_ID, "0");
         int32_t device_id;
         if (ValidationUtil::ValidateStringIsNumber(device_id_str) != SERVER_SUCCESS) {
             std::cerr << "Error: device_id " << device_id_str << " is not a number" << std::endl;
             okay = false;
-        }
-        else {
+        } else {
             device_id = std::stol(device_id_str);
         }
 
@@ -465,16 +473,14 @@ ServerConfig::CheckResourceConfig() {
 
         if (type == "DISK") {
             hasDisk = true;
-        }
-        else if (type == "CPU") {
+        } else if (type == "CPU") {
             hasCPU = true;
             if (resource_conf.GetBoolValue(CONFIG_RESOURCE_ENABLE_EXECUTOR, false)) {
                 hasExecutor = true;
             }
-        }
-        else if(type == "GPU") {
+        } else if (type == "GPU") {
             int build_index_gpu_index = GetConfig(CONFIG_SERVER).GetInt32Value(CONFIG_GPU_INDEX, 0);
-            if(device_id == build_index_gpu_index) {
+            if (device_id == build_index_gpu_index) {
                 resource_valid_flag = true;
             }
             if (resource_conf.GetBoolValue(CONFIG_RESOURCE_ENABLE_EXECUTOR, false)) {
@@ -498,7 +504,7 @@ ServerConfig::CheckResourceConfig() {
         }
     }
 
-    if(!resource_valid_flag) {
+    if (!resource_valid_flag) {
         std::cerr << "Building index GPU can't be found in resource config." << std::endl;
         okay = false;
     }
@@ -510,7 +516,7 @@ ServerConfig::CheckResourceConfig() {
         std::cerr << "No CPU or GPU resource has executor enabled" << std::endl;
         okay = false;
     }
-    
+
     auto connections = resource_config.GetChild(CONFIG_RESOURCE_CONNECTIONS).GetChildren();
     for (auto &connection : connections) {
         auto &connection_conf = connection.second;
@@ -527,8 +533,7 @@ ServerConfig::CheckResourceConfig() {
         if (delimiter_pos == std::string::npos) {
             std::cerr << "Error: invalid endpoint format: " << endpoint_str << std::endl;
             okay = false;
-        }
-        else {
+        } else {
             std::string left_resource = endpoint_str.substr(0, delimiter_pos);
             if (resource_list.find(left_resource) == resource_list.end()) {
                 std::cerr << "Error: left resource " << left_resource << " does not exist" << std::endl;
@@ -547,7 +552,7 @@ ServerConfig::CheckResourceConfig() {
 
 void
 ServerConfig::PrintAll() const {
-    if(const ConfigMgr* mgr = ConfigMgr::GetInstance()) {
+    if (const ConfigMgr *mgr = ConfigMgr::GetInstance()) {
         std::string str = mgr->DumpString();
 //        SERVER_LOG_INFO << "\n" << str;
         std::cout << "\n" << str << std::endl;
@@ -555,16 +560,16 @@ ServerConfig::PrintAll() const {
 }
 
 ConfigNode
-ServerConfig::GetConfig(const std::string& name) const {
-    const ConfigMgr* mgr = ConfigMgr::GetInstance();
-    const ConfigNode& root_node = mgr->GetRootNode();
+ServerConfig::GetConfig(const std::string &name) const {
+    const ConfigMgr *mgr = ConfigMgr::GetInstance();
+    const ConfigNode &root_node = mgr->GetRootNode();
     return root_node.GetChild(name);
 }
 
-ConfigNode&
-ServerConfig::GetConfig(const std::string& name) {
-    ConfigMgr* mgr = ConfigMgr::GetInstance();
-    ConfigNode& root_node = mgr->GetRootNode();
+ConfigNode &
+ServerConfig::GetConfig(const std::string &name) {
+    ConfigMgr *mgr = ConfigMgr::GetInstance();
+    ConfigNode &root_node = mgr->GetRootNode();
     return root_node.GetChild(name);
 }
 
diff --git a/cpp/src/server/ServerConfig.h b/cpp/src/server/ServerConfig.h
index de7c719d98c15f12fba2d44ad95597d5368c5925..b49d788ba942c87c52fcb570ec711d6f6627c99c 100644
--- a/cpp/src/server/ServerConfig.h
+++ b/cpp/src/server/ServerConfig.h
@@ -19,6 +19,7 @@ static const char* CONFIG_SERVER_ADDRESS = "address";
 static const char* CONFIG_SERVER_PORT = "port";
 static const char* CONFIG_CLUSTER_MODE = "mode";
 static const char* CONFIG_GPU_INDEX = "gpu_index";
+static const char* CONFIG_TIME_ZONE = "time_zone";
 
 static const char* CONFIG_DB = "db_config";
 static const char* CONFIG_DB_URL = "db_backend_url";