diff --git a/CMakeLists.txt b/CMakeLists.txt
index 488c38b..f640222 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required (VERSION 3.7)
 project (mastobotmon
-         VERSION 0.0.3
+         VERSION 0.1.0
          LANGUAGES CXX
 )
 
diff --git a/README.md b/README.md
index d425364..5a4d38a 100644
--- a/README.md
+++ b/README.md
@@ -47,10 +47,11 @@ If you use a debug build, you get more verbose error messages.
 # TODO
 
 * Version 0.1.0
-    * [ ] Cron mode
+    * [x] Cron mode
     * [x] Config file
-    * [ ] Alert if account seems inactive
+    * [x] Alert if account seems inactive
 * Version 0.2.0
+    * [ ] Allow to add accounts later
     * [ ] Write mentions to file
 * Version 0.3.0
     * [ ] Write statistics to file
diff --git a/src/mastobotmon.cpp b/src/mastobotmon.cpp
index eeaa06d..9f3a8a2 100644
--- a/src/mastobotmon.cpp
+++ b/src/mastobotmon.cpp
@@ -18,6 +18,10 @@
 #include <string>
 #include <cstdint>
 #include <vector>
+#include <chrono>
+#include <ctime>
+#include <sstream>
+#include <iomanip>  // get_time
 #include <rapidjson/document.h>
 #include "version.hpp"
 #include "mastobotmon.hpp"
@@ -26,6 +30,7 @@ using std::cout;
 using std::cerr;
 using std::cin;
 using std::string;
+using std::uint16_t;
 
 int main(int argc, char *argv[])
 {
@@ -69,8 +74,21 @@ int main(int argc, char *argv[])
                 if (ret == 0)
                 {
                     json.Parse(answer.c_str());
-                    cout << "The last toot of " << json[0]["account"]["acct"].GetString()
-                         << " was at " << json[0]["created_at"].GetString() << ".\n";
+                    const string acct = json[0]["account"]["acct"].GetString();
+
+                    std::istringstream isslast(json[0]["created_at"].GetString());
+                    struct std::tm tm = {0};
+                    isslast >> std::get_time(&tm, "%Y-%m-%dT%T");
+                    std::time_t time = mktime(&tm);
+
+                    const auto now = std::chrono::system_clock::now();
+                    const auto last = std::chrono::system_clock::from_time_t(time);
+                    auto elapsed = std::chrono::duration_cast<std::chrono::minutes>(now - last);
+
+                    if (elapsed.count() > acc.get_minutes())
+                    {
+                        cout << "ALERT: " << acct << " is inactive since " << elapsed.count() << " minutes.\n";
+                    }
                 }
             }
 
diff --git a/src/mastobotmon.hpp b/src/mastobotmon.hpp
index 1197896..8784294 100644
--- a/src/mastobotmon.hpp
+++ b/src/mastobotmon.hpp
@@ -32,7 +32,8 @@ class Account : public Mastodon::API
 {
 public:
     explicit Account(const string &instance, const string &access_token);
-    void set_minutes(uint16_t minutes);
+    const void set_minutes(uint16_t minutes);
+    const uint16_t get_minutes() const;
 
 private:
     uint16_t _minutes;
diff --git a/src/mastodon.cpp b/src/mastodon.cpp
index 872e397..ec05167 100644
--- a/src/mastodon.cpp
+++ b/src/mastodon.cpp
@@ -34,7 +34,12 @@ Account::Account(const string &instance, const string &access_token)
     //
 }
 
-void Account::set_minutes(uint16_t minutes)
+const void Account::set_minutes(uint16_t minutes)
 {
     _minutes = minutes;
 }
+
+const uint16_t Account::get_minutes() const
+{
+    return _minutes;
+}