diff --git a/pandora_agents/unix/DEBIAN/make_deb_package.sh b/pandora_agents/unix/DEBIAN/make_deb_package.sh
index ab4db06828..9a2d9f8549 100644
--- a/pandora_agents/unix/DEBIAN/make_deb_package.sh
+++ b/pandora_agents/unix/DEBIAN/make_deb_package.sh
@@ -42,6 +42,7 @@ mkdir -p temp_package/usr/bin/
 mkdir -p temp_package/usr/sbin/
 mkdir -p temp_package/etc/pandora/plugins
 mkdir -p temp_package/etc/pandora/collections
+mkdir -p temp_package/etc/pandora/ref
 mkdir -p temp_package/etc/pandora/trans
 mkdir -p temp_package/etc/pandora/commands
 mkdir -p temp_package/etc/init.d/
diff --git a/pandora_agents/unix/Darwin/dmg/scripts/postinstall b/pandora_agents/unix/Darwin/dmg/scripts/postinstall
index 5b25222a37..ff930b840c 100644
--- a/pandora_agents/unix/Darwin/dmg/scripts/postinstall
+++ b/pandora_agents/unix/Darwin/dmg/scripts/postinstall
@@ -30,6 +30,7 @@ else
 	mkdir -p /usr/local/share/man/man1/
 	mkdir -p /usr/local/share/pandora_agent/collections/
 	mkdir -p /usr/local/share/pandora_agent/commands/
+	mkdir -p /usr/local/share/pandora_agent/ref/
 	mkdir -p /etc/pandora/
 	mkdir -p /var/spool/pandora/data_out/
 	mkdir -p /var/log/pandora/
@@ -39,6 +40,7 @@ else
 	# Setting permissions to directories and files
 	chmod -R 700 /usr/local/share/pandora_agent/collections
 	chmod -R 700 /usr/local/share/pandora_agent/commands
+	chmod -R 700 /usr/local/share/pandora_agent/ref
 	chmod -R 755 /etc/pandora/
 	chmod -R 700 /var/spool/pandora/data_out
 	chmod -R 711 /var/log/pandora
@@ -69,6 +71,7 @@ chown root:wheel /usr/local/bin/tentacle_client
 ln -s /usr/local/share/pandora_agent/plugins /etc/pandora/plugins
 ln -s /usr/local/share/pandora_agent/commands /etc/pandora/commands
 ln -s /usr/local/share/pandora_agent/collections /etc/pandora/collections
+ln -s /usr/local/share/pandora_agent/ref /etc/pandora/ref
 
 
 # Copy manuals
@@ -90,4 +93,4 @@ echo "/var/log/pandora/pandora_agent.log        :        640        5        204
 # Clean all install utilites
 rm -Rf inst_utilities
 
-exit 0
\ No newline at end of file
+exit 0
diff --git a/pandora_agents/unix/pandora_agent b/pandora_agents/unix/pandora_agent
index 99d1cba038..ac1e32c93c 100755
--- a/pandora_agents/unix/pandora_agent
+++ b/pandora_agents/unix/pandora_agent
@@ -1003,7 +1003,7 @@ use strict;
 use warnings;
 
 use Scalar::Util qw(looks_like_number);
-use POSIX qw(strftime floor);
+use POSIX qw(ceil floor strftime);
 use Sys::Hostname;
 use File::Basename;
 use File::Copy;
@@ -1121,6 +1121,7 @@ my %DefaultConf = (
 	'server_path_md5' => 'md5', #undocumented
 	'server_path_conf' => 'conf', #undocumented
 	'server_path_zip' => 'collections', #undocumented
+	'server_path_ref' => 'ref', #undocumented
 	'logfile' =>'/var/log/pandora/pandora_agent.log',
 	'logsize' => DEFAULT_MAX_LOG_SIZE,
 	'logrotate' => DEFAULT_LOG_ROTATE,
@@ -1569,6 +1570,34 @@ sub parse_conf_modules($) {
 			$module->{'post_process'} = $1;
 		} elsif ($line =~ /^\s*module_interval\s+(\d+)\s*$/) {
 			$module->{'interval'} = $1;
+		} elsif ($line =~ /^\s*module_absoluteinterval\s+(.*)$/) {
+			my $absolute_interval = $1;
+			if ($absolute_interval eq 'once') {
+					$module->{'absoluteinterval'} = 0;
+			} elsif ($absolute_interval =~ /^(\d+)([smhd])?\s*$/) {
+				if (defined($2)) {
+					# Seconds.
+					if ($2 eq 's') {
+						$module->{'absoluteinterval'} = int($1);
+					}
+					# Minutes (convert to seconds).
+					elsif ($2 eq 'm') {
+						$module->{'absoluteinterval'} = int($1) * 60;
+					}
+					# Hours (convert to seconds).
+					elsif ($2 eq 'h') {
+						$module->{'absoluteinterval'} = int($1) * 3600;
+					}
+					# Days (convert to seconds).
+					elsif ($2 eq 'd') {
+						$module->{'absoluteinterval'} = int($1) * 86400;
+					}
+				} else {
+					$module->{'absoluteinterval'} = int($1) * $Conf{'interval'};
+				}
+			} else {
+				log_message ('setup', "Invalid value for module_absoluteinterval: $absolute_interval");
+			}
 		} elsif ($line =~ /^\s*module_timeout\s+(\d+)\s*$/) {
 			$module->{'timeout'} = $1;
 		} elsif ($line =~ /^\s*module_save\s+(\w+)$/) {
@@ -1636,6 +1665,16 @@ sub parse_conf_modules($) {
 				next;
 			}
 
+			# Configure modules with an absolute interval.
+			if (defined($module->{'absoluteinterval'})) {
+
+				# Convert from seconds to actual agent intervals.
+				$module->{'interval'} = ceil($module->{'absoluteinterval'} / $Conf{'interval'});
+
+				# This file will be used for persistence.
+				$module->{'timestamp_file'} = $ConfDir . '/' . $Conf{'server_path_ref'} . '/' . md5($module->{'name'}) . '.ref';
+			}
+
 			# Set the intensive interval
 			if ($module->{'is_intensive'} == 1) {				
 				$module->{'intensive_interval'} = $module->{'interval'};
@@ -1643,9 +1682,9 @@ sub parse_conf_modules($) {
 				$module->{'intensive_interval'} = $module->{'interval'} * ($Conf{'interval'} / $Conf{'intensive_interval'});
 			}
 
-			# Make the module run the first time
-			$module->{'counter'} = $module->{'intensive_interval'};
-			
+			# Initialize the module's execution counter.
+			init_counter($module);
+
 			# Replace macros
 			replace_macros ($module);
 
@@ -2805,7 +2844,15 @@ sub exec_module {
 		}
 	}
 
-	if (++($module->{'counter'}) < $module->{'intensive_interval'}) {
+	# Modules that will run once.
+	if ($module->{'interval'} == 0) {
+		if ($module->{'counter'} == 0) {
+			$ThreadSem->up () if (defined ($ThreadSem) && $Conf{'agent_threads'} > 1);
+			return;
+		}
+	}
+	# Modules that will run periodically.
+	elsif (++($module->{'counter'}) < $module->{'intensive_interval'}) {
 		$ThreadSem->up () if (defined ($ThreadSem) && $Conf{'agent_threads'} > 1);
 		return;
 	}
@@ -2862,6 +2909,9 @@ sub exec_module {
 		}
 	}
 	
+	# Save the module's timestamp to disk.
+	save_module_timestamp($module);
+
 	$ThreadSem->up () if (defined ($ThreadSem) && $Conf{'agent_threads'} > 1);
 }
 
@@ -3547,6 +3597,44 @@ sub check_module_cron {
 	return 0;
 }
 
+################################################################################
+# Initialize a module's internal execution counter.
+################################################################################
+sub init_counter($) {
+	my ($module) = @_;
+	
+	# Open the timestamp file if available.
+	my $fh;
+	if (!defined($module->{'timestamp_file'}) || 
+	    !open($fh, '<', $module->{'timestamp_file'})) {
+		# If intensive_interval is 0, setting counter to any value != 0 will make the module run.
+		$module->{'counter'} = $module->{'intensive_interval'} == 0 ? 1 : $module->{'intensive_interval'};
+		return;
+	}
+
+	# Read the timestamp from disk.
+	my $timestamp = int(<$fh>);
+	close($fh);
+
+	# Update the module's execution counter.
+	# If intensive_interval is 0, setting counter to 0 will prevent the module from running again.
+	$module->{'counter'} = $module->{'intensive_interval'} == 0 ? 0 : floor((time() - $timestamp) / $Conf{'interval'});
+}
+
+################################################################################
+# Save a module's execution timestamp to disk for persistence.
+################################################################################
+sub save_module_timestamp($) {
+	my ($module) = @_;
+
+	return if (!defined($module->{'timestamp_file'}));
+
+	# Update the time reference.
+	open(my $fh, '>', $module->{'timestamp_file'}) or return;
+	print $fh time();
+	close($fh);
+}
+
 ################################################################################
 # Write module data in XML format.
 ################################################################################
diff --git a/pandora_agents/unix/pandora_agent.redhat.spec b/pandora_agents/unix/pandora_agent.redhat.spec
index aca51417b3..c0aa33d101 100644
--- a/pandora_agents/unix/pandora_agent.redhat.spec
+++ b/pandora_agents/unix/pandora_agent.redhat.spec
@@ -100,6 +100,11 @@ if [ ! -e /etc/pandora/collections ]; then
 	ln -s /usr/share/pandora_agent/collections /etc/pandora
 fi
 
+if [ ! -e /etc/pandora/ref ]; then
+	mkdir -p /usr/share/pandora_agent/ref
+	ln -s /usr/share/pandora_agent/ref /etc/pandora
+fi
+
 if [ ! -e /etc/pandora/commands ]; then
 	mkdir -p /usr/share/pandora_agent/commands
 	ln -s /usr/share/pandora_agent/commands /etc/pandora
@@ -143,7 +148,7 @@ fi
 
 # Remove symbolic links
 pushd /etc/pandora
-for f in pandora_agent.conf plugins collections
+for f in pandora_agent.conf plugins collections ref
 do
 	[ -L $f ] && rm -f $f
 done
diff --git a/pandora_agents/unix/pandora_agent.spec b/pandora_agents/unix/pandora_agent.spec
index e8c0c58201..bb2c72ea70 100644
--- a/pandora_agents/unix/pandora_agent.spec
+++ b/pandora_agents/unix/pandora_agent.spec
@@ -94,6 +94,10 @@ if [ ! -e /etc/pandora/collections ]; then
 	mkdir /etc/pandora/collections
 fi
 
+if [ ! -e /etc/pandora/ref ]; then
+	mkdir /etc/pandora/ref
+fi
+
 if [ ! -e /etc/pandora/commands ]; then
 	mkdir /etc/pandora/commands
 fi
diff --git a/pandora_agents/unix/pandora_agent_installer b/pandora_agents/unix/pandora_agent_installer
index cf7642e0e6..0edb6ca446 100755
--- a/pandora_agents/unix/pandora_agent_installer
+++ b/pandora_agents/unix/pandora_agent_installer
@@ -408,6 +408,11 @@ install () {
 	chmod -R 700 $PANDORA_BASE$PANDORA_HOME/commands
 	ln -s $PANDORA_BASE_REAL$PANDORA_HOME/commands $PANDORA_BASE$PANDORA_CFG
 	
+	echo "Creating the ref directory in to $PANDORA_BASE$PANDORA_HOME/ref..."
+	mkdir -p $PANDORA_BASE$PANDORA_HOME/ref
+	chmod -R 700 $PANDORA_BASE$PANDORA_HOME/ref
+	ln -s $PANDORA_BASE_REAL$PANDORA_HOME/ref $PANDORA_BASE$PANDORA_CFG
+
 	if [ $WITHOUT_TENTACLE_SERVER -eq 0 ]
 	then
 		echo "Copying tentacle server to $PANDORA_BASE$TENTACLE_SERVER"
diff --git a/pandora_agents/win32/misc/pandora_file.h b/pandora_agents/win32/misc/pandora_file.h
index 5099168911..9a4c83832a 100644
--- a/pandora_agents/win32/misc/pandora_file.h
+++ b/pandora_agents/win32/misc/pandora_file.h
@@ -31,6 +31,10 @@ using namespace std;
  * File operations.
  */
 namespace Pandora_File {
+
+	/* Size of a buffer that will be passed to Pandora_File::md5. */
+	const int MD5_BUF_SIZE = 33;
+
 	/**
 	 * File super-class exception.
 	 */
diff --git a/pandora_agents/win32/modules/pandora_module.cc b/pandora_agents/win32/modules/pandora_module.cc
index 4a6382acf6..fb701fae7c 100644
--- a/pandora_agents/win32/modules/pandora_module.cc
+++ b/pandora_agents/win32/modules/pandora_module.cc
@@ -19,11 +19,14 @@
 */
 
 #include "pandora_module.h"
+#include "pandora_windows_service.h"
+#include "../misc/pandora_file.h"
 #include "../pandora_strutils.h"
 #include "../pandora.h"
 
 #include <iostream>
 #include <sstream>
+#include <cmath>
 
 #define BUFSIZE 4096 
 
@@ -472,18 +475,27 @@ Pandora_Module::setNoOutput () {
  */
 void
 Pandora_Module::run () {
-	/* Check the interval */
-	if (this->executions % this->intensive_interval != 0) {
+
+	// Run once.
+	if (this->intensive_interval == 0) {
+		if (this->executions == 0) {
+			has_output = false;
+			throw Interval_Not_Fulfilled ();
+		}
+	}
+	// Run periodically.
+	else if (++this->executions < this->intensive_interval) {
 		pandoraDebug ("%s: Interval is not fulfilled", this->module_name.c_str ());
-		this->executions++;
 		has_output = false;
 		throw Interval_Not_Fulfilled ();
 	} 
 	
-	/* Increment the executions after check. This is done to execute the
-	   first time */
-	this->executions++;
+	// Reset the execution counter.
+	this->executions = 0;
 	has_output = true;
+
+	// Update the execution timestamp.
+	this->updateTimestampFile();
 }
 
 /** 
@@ -1663,6 +1675,63 @@ Pandora_Module::getTimestamp () {
 	return this->timestamp;
 }
 
+/** 
+ * Sets the module timestamp file.
+ * 
+ * @param file_name The name of the timestamp file.
+ */
+void
+Pandora_Module::setTimestampFile (string file_name) {
+	this->timestamp_file = file_name;
+}
+
+/** 
+ * Gets the module timestamp file.
+ * 
+ * @return The name of the timestamp file.
+ */
+string
+Pandora_Module::getTimestampFile () {
+	return this->timestamp_file;
+}
+
+/** 
+ * Update the timestamp file with the current time.
+ * 
+ */
+void
+Pandora_Module::updateTimestampFile () {
+	try {
+		Pandora_File::writeFile(this->timestamp_file, std::to_string(std::time(NULL)));
+	} catch (...) {
+		/* Ignore errors. */
+	}
+}
+
+/** 
+ * Initialize the module's internal execution counter.
+ * 
+ */
+void
+Pandora_Module::initExecutions () {
+	string timestamp;
+
+	try {
+		if (this->timestamp_file != "" && Pandora_File::readFile(this->timestamp_file, timestamp) != FILE_NOT_FOUND) {
+			// If the interval is 0, setting executions to 0 will prevent the module from running.
+			this->executions = this->intensive_interval == 0 ?
+				0 :
+				floor((1000.0 * (std::time(NULL) - strtoint(timestamp))) / Pandora_Windows_Service::getInstance()->getInterval());
+			return;
+		}
+	} catch (...) {
+		// Ignore errors.
+	}
+
+	// If the interval is 0, setting executions to any value != 0 will make the module run.
+	this->executions = this->intensive_interval == 0 ? 1 : this->intensive_interval;
+}
+
 /** 
  * Sets the value of intensive_match.
  * 
diff --git a/pandora_agents/win32/modules/pandora_module.h b/pandora_agents/win32/modules/pandora_module.h
index 026e539ff1..ed4f0a7bfa 100644
--- a/pandora_agents/win32/modules/pandora_module.h
+++ b/pandora_agents/win32/modules/pandora_module.h
@@ -171,6 +171,7 @@ namespace Pandora_Modules {
 		Cron				  *cron;
 		list<Condition *>     *intensive_condition_list;
 		time_t                timestamp;
+		string                timestamp_file;
 		unsigned char         intensive_match;
 		int                   intensive_interval;
 		string                unit, custom_id, str_warning, str_critical;
@@ -238,6 +239,7 @@ namespace Pandora_Modules {
 		bool         getAsync ();
 		void         setExecutions(long executions=0);
 		long         getExecutions();
+		void         initExecutions ();
 
 		virtual string getXml      ();
 
@@ -303,6 +305,9 @@ namespace Pandora_Modules {
 		int         hasOutput ();
 		void        setTimestamp (time_t timestamp);
 		time_t      getTimestamp ();
+		void        setTimestampFile (string file_name);
+		string      getTimestampFile ();
+		void        updateTimestampFile ();
 		void        setIntensiveMatch (unsigned char intensive_match);
 		unsigned char getIntensiveMatch ();
 		bool        isIntensive ();
diff --git a/pandora_agents/win32/modules/pandora_module_factory.cc b/pandora_agents/win32/modules/pandora_module_factory.cc
index 022f971388..30bd92bb09 100644
--- a/pandora_agents/win32/modules/pandora_module_factory.cc
+++ b/pandora_agents/win32/modules/pandora_module_factory.cc
@@ -41,7 +41,10 @@
 #include "pandora_module_snmpget.h"
 #include "../windows/pandora_wmi.h"
 #include "../pandora_strutils.h"
+#include "../misc/pandora_file.h"
+#include "../pandora.h"
 #include <list>
+#include <cmath>
 
 using namespace Pandora;
 using namespace Pandora_Modules;
@@ -50,6 +53,7 @@ using namespace Pandora_Strutils;
 #define TOKEN_NAME          ("module_name ")
 #define TOKEN_TYPE          ("module_type ")
 #define TOKEN_INTERVAL      ("module_interval ")
+#define TOKEN_ABSOLUTEINTERVAL ("module_absoluteinterval ")
 #define TOKEN_EXEC          ("module_exec ")
 #define TOKEN_PROC          ("module_proc ")
 #define TOKEN_SERVICE       ("module_service ")
@@ -156,7 +160,8 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 	list<string>::iterator iter;
 	string                 module_name, module_type, module_exec;
 	string                 module_min, module_max, module_description;
-	string                 module_interval, module_proc, module_service;
+	string                 module_interval, module_absoluteinterval;
+	string                 module_proc, module_service;
 	string                 module_freedisk, module_cpuusage, module_inventory;
 	string                 module_freedisk_percent, module_freememory_percent;
 	string                 module_dsn, module_freememory;
@@ -196,6 +201,7 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 	module_max           = "";
 	module_description   = "";
 	module_interval      = "";
+	module_absoluteinterval = "";
 	module_exec          = "";
 	module_proc          = "";
 	module_service       = "";
@@ -290,6 +296,9 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 		if (module_interval == "") {
 			module_interval = parseLine (line, TOKEN_INTERVAL);
 		}
+		if (module_absoluteinterval == "") {
+			module_absoluteinterval = parseLine (line, TOKEN_ABSOLUTEINTERVAL);
+		}
 		if (module_exec == "") {
 			module_exec = parseLine (line, TOKEN_EXEC);
 		}
@@ -603,6 +612,13 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 					}
 				}
 
+				if (module_absoluteinterval != "") {
+					pos_macro = module_absoluteinterval.find(macro_name);
+					if (pos_macro != string::npos){
+						module_absoluteinterval.replace(pos_macro, macro_name.size(), macro_value);
+					}
+				}
+
 				if (module_exec != "") {
 					pos_macro = module_exec.find(macro_name);
 					if (pos_macro != string::npos){
@@ -1323,6 +1339,61 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 		}
 	}
 
+	/* Set the module absolute interval */
+	if (module_absoluteinterval != "") {
+		int interval;
+		
+		try {
+			service = Pandora_Windows_Service::getInstance();
+
+			// Run once.
+			if (module_absoluteinterval == "once") {
+				interval = 0;
+			}
+			// Seconds.
+			else if (module_absoluteinterval.back() == 's') {
+				interval = strtoint (module_absoluteinterval.substr(0, module_absoluteinterval.size() - 1));
+			}
+			// Minutes.
+			else if (module_absoluteinterval.back() == 'm') {
+				interval = strtoint (module_absoluteinterval.substr(0, module_absoluteinterval.size() - 1)) * 60;
+			}
+			// Hours.
+			else if (module_absoluteinterval.back() == 'h') {
+				interval = strtoint (module_absoluteinterval.substr(0, module_absoluteinterval.size() - 1)) * 3600;
+			}
+			// Days.
+			else if (module_absoluteinterval.back() == 'd') {
+				interval = strtoint (module_absoluteinterval.substr(0, module_absoluteinterval.size() - 1)) * 86400;
+			}
+			// Number of agent intervals.
+			else {
+				interval = strtoint(module_absoluteinterval) * (service->getIntervalSec());
+			}
+
+			// Convert from seconds to agent executions.
+			interval = ceil(interval / double(service->getIntervalSec()));
+
+			// Set the module interval.
+			module->setInterval (interval);
+			module->setIntensiveInterval (interval);
+
+			// Compute the MD5 hash of the module's name.
+			char module_name_md5[Pandora_File::MD5_BUF_SIZE];
+			Pandora_File::md5(module_name.c_str(), module_name.size(), module_name_md5);
+
+			// Set the timestamp file.
+			module->setTimestampFile(Pandora::getPandoraInstallDir().append("/ref/").append(module_name_md5).append(".ref"));
+		} catch (Invalid_Conversion e) {
+			pandoraLog ("Invalid absolute interval value \"%s\" for module %s",
+			module_absoluteinterval.c_str (),
+			module_name.c_str ());
+		}
+		catch (...) {
+			// Should not happen. Ignore errors.
+		}
+	}
+
 	/* Module intensive condition */
 	if (intensive_condition_list.size () > 0) {
 		intensive_condition_iter = intensive_condition_list.begin ();
@@ -1337,6 +1408,9 @@ Pandora_Module_Factory::getModuleFromDefinition (string definition) {
 		module->setIntensiveInterval (module->getInterval () * (service->getInterval () / service->getIntensiveInterval ()));
 	}
 
+	/* Initialize the module's execution counter. */
+	module->initExecutions ();
+
 	/* Module cron */
 	module->setCron (module_crontab);
 
diff --git a/pandora_agents/win32/pandora_windows_service.cc b/pandora_agents/win32/pandora_windows_service.cc
index f369935aac..3b15556059 100644
--- a/pandora_agents/win32/pandora_windows_service.cc
+++ b/pandora_agents/win32/pandora_windows_service.cc
@@ -2197,6 +2197,11 @@ Pandora_Windows_Service::getInterval () {
 	return this->interval;
 }
 
+long
+Pandora_Windows_Service::getIntervalSec () {
+	return this->interval_sec;
+}
+
 long
 Pandora_Windows_Service::getIntensiveInterval () {
 	return this->intensive_interval;
diff --git a/pandora_agents/win32/pandora_windows_service.h b/pandora_agents/win32/pandora_windows_service.h
index f863ae2c27..63d83f490b 100644
--- a/pandora_agents/win32/pandora_windows_service.h
+++ b/pandora_agents/win32/pandora_windows_service.h
@@ -122,6 +122,7 @@ namespace Pandora {
 		Pandora_Agent_Conf *getConf ();
 		string         getEHKey (string ehorus_conf);
 		long           getInterval ();
+		long           getIntervalSec ();
 		long           getIntensiveInterval ();
 		string         generateAgentName ();
 		bool           writeToBuffer (string temporal);