diff --git a/Makefile.PL b/Makefile.PL
index 5106f9d..efe153d 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -26,5 +26,6 @@ WriteMakefile(
         'v5.30.0' => '0',
         'warnings' => '0',
         'DBD::SQLite' => 0,
+        'DateTime::Format::ISO8601' => 0,
     },
 );
diff --git a/bin/doctor_karma.pl b/bin/doctor_karma.pl
index e51f9cf..dd3b7a3 100755
--- a/bin/doctor_karma.pl
+++ b/bin/doctor_karma.pl
@@ -129,13 +129,36 @@ sub process_message_with_text {
     }
 }
 
+sub check_can_modify_karma {
+    my $message = shift;
+    my $user_id = $message->{from}{id};
+    my $chat_id = $message->{chat}{id};
+
+    my $user_dao = DoctorKarma::DAO::User->new( dbh => $db );
+    my $user    = $user_dao->recover_id( id => $user_id );
+
+    if ( $user->can_modify_karma ) {
+        $user_dao->update_last_karma_given_date(
+            user                  => $user,
+            last_karma_given_date => DateTime->now
+        );
+        return 1;
+    }
+    $telegram->send_message(
+        chat_id => $chat_id,
+        text    => "You cannot give karma yet wait a bit.",
+    );
+    return 0;
+}
+
 sub show_help {
     my $message = shift;
     my $chat_id = $message->{chat}{id};
 
     my $html = "<b><u>List of commands</u></b>\n\n";
     for my $command (@commands) {
-        $html .= "<b>@{[xml_escape('/'.$command->{command})]}</b> @{[xml_escape($command->{description})]}\n";
+        $html .=
+"<b>@{[xml_escape('/'.$command->{command})]}</b> @{[xml_escape($command->{description})]}\n";
     }
     $telegram->send_message(
         text    => $html,
@@ -272,7 +295,7 @@ EOF
         );
         return;
     }
-
+    return unless check_can_modify_karma($message);
     my $receiving_karma_user =
       $user_dao->recover_id( id => $user_receiving_id );
     if ( !defined $receiving_karma_user ) {
@@ -315,6 +338,7 @@ EOF
         return;
     }
 
+    return unless check_can_modify_karma($message);
     my $receiving_karma_user =
       $user_dao->recover_id( id => $user_receiving_id );
     if ( !defined $receiving_karma_user ) {
diff --git a/lib/DoctorKarma/DAO/User.pm b/lib/DoctorKarma/DAO/User.pm
index bce012d..86934b0 100644
--- a/lib/DoctorKarma/DAO/User.pm
+++ b/lib/DoctorKarma/DAO/User.pm
@@ -8,6 +8,8 @@ use warnings;
 use Types::Standard qw/Str Int InstanceOf ArrayRef Maybe HasMethods/;
 use Params::ValidationCompiler qw(validation_for);
 
+use DateTime::Format::ISO8601;
+
 {
     my $validator = validation_for(
         params => {
@@ -58,7 +60,7 @@ EOF
         my $username = "\@@{[$user->username]}:" // '';
         my $user_id  = $user->id_user;
         $logger->log_info("Trying to register ${username}${user_id}.");
-        my $success  = 0 +
+        my $success = 0 +
           $db->do( $insert, {}, $user->id_user, $user->username, $user->karma );
         if ($success) {
             $logger->log_info("${username}${user_id} registered.");
@@ -153,7 +155,7 @@ EOF
         $user->karma( $user_with_new_karma->karma );
         $logger->log_info( 'User '
               . $user->first_name . ':'
-              . ($user->username // '') . ':'
+              . ( $user->username // '' ) . ':'
               . $user->id_user
               . ' has now '
               . $user->karma
@@ -161,6 +163,32 @@ EOF
     }
 }
 
+{
+    my $validator = validation_for(
+        params => {
+            user => { type => InstanceOf ['DoctorKarma::Model::User'] },
+            last_karma_given_date =>
+              { type => InstanceOf ['DateTime'], optional => 1 },
+        }
+    );
+
+    sub update_last_karma_given_date {
+        my $self   = shift;
+        my %params = $validator->(@_);
+        my $db     = $self->_db;
+
+        my $last_karma_given_date = $params{last_karma_given_date};
+        my $user                  = $params{user};
+
+        $db->do( <<'EOF', {}, $last_karma_given_date . '', $user->id_user );
+UPDATE users SET last_karma_given_date=? WHERE id = ?;
+EOF
+        my $user_with_new_last_karma =
+          $self->recover_id( id => $user->id_user );
+        $user->last_karma_given_date( $user->last_karma_given_date );
+    }
+}
+
 {
     my $validator = validation_for(
         params => {
@@ -306,6 +334,11 @@ EOF
             for my $key_field ( keys %$user_db ) {
                 $user_db->{$key_field} // delete $user_db->{$key_field};
             }
+            if ( defined $user_db->{last_karma_given_date} ) {
+                my $iso8601 = DateTime::Format::ISO8601->new;
+                $user_db->{last_karma_given_date} =
+                  $iso8601->parse_datetime( $user_db->{last_karma_given_date} );
+            }
             return DoctorKarma::Model::User->new(%$user_db);
         }
         return undef;
diff --git a/lib/DoctorKarma/Model/User.pm b/lib/DoctorKarma/Model/User.pm
index 44284b0..e266cd9 100644
--- a/lib/DoctorKarma/Model/User.pm
+++ b/lib/DoctorKarma/Model/User.pm
@@ -8,6 +8,8 @@ use warnings;
 use Types::Standard qw/Str Int InstanceOf/;
 use Params::ValidationCompiler qw(validation_for);
 
+use DateTime;
+
 {
     my $validator = validation_for(
         params => {
@@ -15,7 +17,8 @@ use Params::ValidationCompiler qw(validation_for);
             username              => { type => Str, optional => 1 },
             first_name            => { type => Str, optional => 1 },
             karma                 => { type => Int },
-            last_karma_given_date => { type => InstanceOf ['DateTime'], optional => 1 },
+            last_karma_given_date =>
+              { type => InstanceOf ['DateTime'], optional => 1 },
         }
     );
 
@@ -27,10 +30,19 @@ use Params::ValidationCompiler qw(validation_for);
     }
 }
 
+sub can_modify_karma {
+    my $self                  = shift;
+    my $last_karma_given_date = $self->last_karma_given_date;
+    if ( !defined $last_karma_given_date ) {
+        return 1;
+    }
+    return DateTime->now >
+      $self->last_karma_given_date->clone->add( minutes => 1 );
+}
 
 sub first_name {
-    my $self   = shift;
-    if (exists $self->{first_name}) {
+    my $self = shift;
+    if ( exists $self->{first_name} ) {
         return $self->{first_name};
     }
     return undef;
@@ -58,9 +70,19 @@ sub id_user {
     }
 }
 
-sub last_karma_given_date {
-    my $self = shift;
-    return $self->{last_karma_given_date};
+{
+    my $validator =
+      validation_for(
+        params => [ { type => InstanceOf ['DateTime'], optional => 1} ] );
+
+    sub last_karma_given_date {
+        my $self = shift;
+        my ($last_karma_given_date) = $validator->(@_);
+        if ( defined $last_karma_given_date ) {
+            $self->{last_karma_given_date} = $last_karma_given_date;
+        }
+        return $self->{last_karma_given_date};
+    }
 }
 
 {