diff --git a/src/hack/concepts/concepts.hpp b/src/hack/concepts/concepts.hpp
index cc408f8..5367ee2 100755
--- a/src/hack/concepts/concepts.hpp
+++ b/src/hack/concepts/concepts.hpp
@@ -7,6 +7,7 @@
 #include <unordered_set>
 #include <unordered_map>
 #include <forward_list>
+#include <string_view>
 
 #include <concepts>
 
@@ -48,5 +49,4 @@ namespace hack::concepts
                                             is_forward_list<T> ||
                                             std::is_array<T>() ||
                                             is_string<T>), bool>() ==  true;
-
 }
diff --git a/src/hack/exception/exception.hpp b/src/hack/exception/exception.hpp
index eb7d202..94f96aa 100644
--- a/src/hack/exception/exception.hpp
+++ b/src/hack/exception/exception.hpp
@@ -25,24 +25,24 @@ namespace hack
 
       void log()
       {
-        std::cout << view::color::bold << view::color::red <<"["+m_service+"] " << view::color::reset
+        std::cout << utils::color::bold << utils::color::red <<"["+m_service+"] " << utils::color::reset
                   << m_location.file_name() << ":" 
-                  << view::color::italic << view::color::yellow << m_location.function_name() << "()" << view::color::reset
-                  << view::color::bold << view::color::blue << "[" << m_location.line() << "]" << view::color::reset << ": "
+                  << utils::color::italic << utils::color::yellow << m_location.function_name() << "()" << utils::color::reset
+                  << utils::color::bold << utils::color::blue << "[" << m_location.line() << "]" << utils::color::reset << ": "
                   << m_title << std::endl;
 
         if (!m_description.empty())
-          std::cout << view::color::bold << view::color::red <<"["+m_service+"] " << view::color::reset
+          std::cout << utils::color::bold << utils::color::red <<"["+m_service+"] " << utils::color::reset
                     << m_location.file_name() << ":" 
-                    << view::color::italic << view::color::yellow << m_location.function_name() << "()" << view::color::reset
-                    << view::color::bold << view::color::blue << "[" << m_location.line() << "]" << view::color::reset << ": "
+                    << utils::color::italic << utils::color::yellow << m_location.function_name() << "()" << utils::color::reset
+                    << utils::color::bold << utils::color::blue << "[" << m_location.line() << "]" << utils::color::reset << ": "
                     << m_description << std::endl;
         
         if (!m_system_error.empty())
-          std::cout << view::color::bold << view::color::red <<"["+m_service+"] " << view::color::reset
+          std::cout << utils::color::bold << utils::color::red <<"["+m_service+"] " << utils::color::reset
                     << m_location.file_name() << ":" 
-                    << view::color::italic << view::color::yellow << m_location.function_name() << "()" << view::color::reset
-                    << view::color::bold << view::color::blue << "[" << m_location.line() << "]" << view::color::reset << ": "
+                    << utils::color::italic << utils::color::yellow << m_location.function_name() << "()" << utils::color::reset
+                    << utils::color::bold << utils::color::blue << "[" << m_location.line() << "]" << utils::color::reset << ": "
                     << m_system_error << std::endl;
       }
 
diff --git a/src/hack/logger/logger.hpp b/src/hack/logger/logger.hpp
index ac3c0f2..6a65166 100755
--- a/src/hack/logger/logger.hpp
+++ b/src/hack/logger/logger.hpp
@@ -42,16 +42,16 @@ namespace hack
       void prepare(T t, U u)
       {
         std::cout << t
-                  << u.file_name() << ":" << view::color::reset 
-                  << view::color::italic << view::color::yellow << u.function_name() << "()" << view::color::reset
-                  << view::color::bold << view::color::blue << "[" << u.line() << "]" << view::color::reset << ": ";
+                  << u.file_name() << ":" << utils::color::reset 
+                  << utils::color::italic << utils::color::yellow << u.function_name() << "()" << utils::color::reset
+                  << utils::color::bold << utils::color::blue << "[" << u.line() << "]" << utils::color::reset << ": ";
       }
 
       static void print() { std::cout << std::endl; }
 
       static std::ostream& make_type_view(std::ostream &os)
       {
-        os << view::color::bold << view::color::green << "[ok]" << view::color::reset << view::color::green;
+        os << utils::color::bold << utils::color::green << "[ok]" << utils::color::reset << utils::color::green;
         return os;
       }
 
@@ -171,7 +171,7 @@ namespace hack
     private:
       static std::ostream& make_type_view(std::ostream &os)
       {
-        os << view::color::bold << view::color::yellow << "[WARN]" << view::color::reset << view::color::yellow;
+        os << utils::color::bold << utils::color::yellow << "[WARN]" << utils::color::reset << utils::color::yellow;
         return os;
       }
   };
@@ -201,7 +201,7 @@ namespace hack
     private:
       static std::ostream& make_type_view(std::ostream &os)
       {
-        os << view::color::bold <<  view::color::red << "[ERROR]" << view::color::reset << view::color::red;
+        os << utils::color::bold <<  utils::color::red << "[ERROR]" << utils::color::reset << utils::color::red;
         return os;
       }
   };
diff --git a/src/hack/utils/color.hpp b/src/hack/utils/color.hpp
index 3f3d37d..6173e3f 100755
--- a/src/hack/utils/color.hpp
+++ b/src/hack/utils/color.hpp
@@ -2,7 +2,7 @@
 
 #include <iostream>
 
-namespace hack::view::color
+namespace hack::utils::color
 {
   template<typename CharT, typename Traits>
   std::basic_ostream<CharT, Traits>& reset(std::basic_ostream<CharT, Traits> &os)
diff --git a/src/hack/utils/timestamp.hpp b/src/hack/utils/timestamp.hpp
new file mode 100644
index 0000000..772a29b
--- /dev/null
+++ b/src/hack/utils/timestamp.hpp
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <string>
+#include <chrono>
+
+namespace hack::utils
+{
+  // return current time
+  inline std::string timestamp() 
+  {
+    auto now = std::chrono::system_clock::now();
+    auto in_time_t = std::chrono::system_clock::to_time_t(now);
+    std::stringstream ss;
+    ss << std::put_time(std::localtime(&in_time_t), "%Y-%m-%d-%H.%M.%S");
+    return ss.str();
+  }
+}