diff --git a/htdocs/contrat/class/contrat.class.php b/htdocs/contrat/class/contrat.class.php
index 63bedcfdcbc..088d8f9b6d5 100644
--- a/htdocs/contrat/class/contrat.class.php
+++ b/htdocs/contrat/class/contrat.class.php
@@ -2600,6 +2600,177 @@ class Contrat extends CommonObject
 			return -1;
 		}
 	}
+
+
+	/**
+	 * Action executed by scheduler
+	 * CAN BE A CRON TASK
+	 * Loop on each contract lines and update the end of date. Do not execute the update if there is one pending invoice linked to contract.
+	 *
+	 * @param	int		$thirdparty_id			Thirdparty id
+	 * @param	int		$delayindaysshort 		To renew the resources x day before (positive value) or after (negative value) the end of date (default is 0)
+	 * @return	int								0 if OK, <>0 if KO (this function is used also by cron so only 0 is OK)
+	 */
+	public function doAutoRenewContracts($thirdparty_id = 0, $delayindaysshort = 0)
+	{
+		global $langs, $user;
+
+		$langs->load("agenda");
+
+		$now = dol_now();
+
+		$enddatetoscan = dol_time_plus_duree($now, -1 * abs($delayindaysshort), 'd');
+
+		$error = 0;
+		$this->output = '';
+		$this->error='';
+
+		$contractlineprocessed = array();
+		$contractignored = array();
+		$contracterror = array();
+
+		dol_syslog(__METHOD__, LOG_DEBUG);
+
+		$sql = 'SELECT c.rowid, c.ref_customer, cd.rowid as lid, cd.date_fin_validite, p.duration';
+		$sql.= ' FROM '.MAIN_DB_PREFIX.'contrat as c, '.MAIN_DB_PREFIX.'contratdet as cd';
+		$sql.= ' LEFT JOIN '.MAIN_DB_PREFIX.'product as p ON p.rowid = cd.fk_product';
+		$sql.= ' WHERE cd.fk_contrat = c.rowid';
+		$sql.= " AND date_format(cd.date_fin_validite, '%Y-%m-%d') <= date_format('".$this->db->idate($enddatetoscan)."', '%Y-%m-%d')";
+		$sql.= " AND cd.statut = 4";
+		if ($thirdparty_id > 0) $sql.=" AND c.fk_soc = ".((int) $thirdparty_id);
+		//print $sql;
+
+		$resql = $this->db->query($sql);
+		if ($resql) {
+			$num = $this->db->num_rows($resql);
+
+			include_once DOL_DOCUMENT_ROOT.'/core/class/html.formmail.class.php';
+
+			$i=0;
+			while ($i < $num) {
+				$obj = $this->db->fetch_object($resql);
+				if ($obj) {
+					if (! empty($contractlineprocessed[$obj->lid]) || ! empty($contractignored[$obj->rowid]) || ! empty($contracterror[$obj->rowid])) {
+						continue;
+					}
+
+					// Load contract
+					$object = new Contrat($this->db);
+					$object->fetch($obj->rowid);		// fetch also lines
+					$object->fetch_thirdparty();
+
+					if ($object->id <= 0) {
+						$error++;
+						$this->errors[] = 'Failed to load contract with id='.$obj->rowid;
+						continue;
+					}
+
+					dol_syslog("* Process contract line in doRenewalContracts for contract id=".$object->id." ref=".$object->ref." ref_customer=".$object->ref_customer." contract line id=".$obj->lid);
+
+					// Update expiration date of line
+					$expirationdate = $this->db->jdate($obj->date_fin_validite);
+					$duration_value = preg_replace('/[^0-9]/', '', $obj->duration);
+					$duration_unit = preg_replace('/\d/', '', $obj->duration);
+					//var_dump($expirationdate.' '.$enddatetoscan);
+
+					// Test if there is pending invoice
+					$object->fetchObjectLinked(null, '', null, '', 'OR', 1, 'sourcetype', 1);
+
+					if (is_array($object->linkedObjects['facture']) && count($object->linkedObjects['facture']) > 0) {
+						usort($object->linkedObjects['facture'], "cmp");
+
+						//dol_sort_array($contract->linkedObjects['facture'], 'date');
+						$someinvoicenotpaid=0;
+						foreach ($object->linkedObjects['facture'] as $idinvoice => $invoice) {
+							if ($invoice->statut == Facture::STATUS_DRAFT) continue;	// Draft invoice are not invoice not paid
+
+							if (empty($invoice->paye)) {
+								$someinvoicenotpaid++;
+							}
+						}
+						if ($someinvoicenotpaid) {
+							$this->output .= 'Contract '.$object->ref.' is qualified for renewal but there is '.$someinvoicenotpaid.' invoice(s) unpayed so we cancel renewal'."\n";
+							$contractignored[$object->id]=$object->ref;
+							continue;
+						}
+					}
+
+					if ($expirationdate && $expirationdate < $enddatetoscan) {
+						dol_syslog("Define the newdate of end of services from expirationdate=".$expirationdate);
+						$newdate = $expirationdate;
+						$protecti=0;	//$protecti is to avoid infinite loop
+						while ($newdate < $enddatetoscan && $protecti < 1000) {
+							$newdate = dol_time_plus_duree($newdate, $duration_value, $duration_unit);
+							$protecti++;
+						}
+
+						if ($protecti < 1000) {	// If not, there is a pb
+							// We will update the end of date of contrat, so first we refresh contract data
+							dol_syslog("We will update the end of date of contract with newdate = ".dol_print_date($newdate, 'dayhourrfc'));
+
+							$this->db->begin();
+
+							$errorforlocaltransaction = 0;
+
+							$label = 'Renewal of contrat '.$object->ref.' line '.$obj->lid;
+							$comment = 'Renew date of contract '.$object->ref.' line '.$obj->lid.' by doAutoRenewContracts';
+
+							$sqlupdate = 'UPDATE '.MAIN_DB_PREFIX."contratdet SET date_fin_validite = '".$this->db->idate($newdate)."'";
+							$sqlupdate.= ' WHERE rowid = '.((int) $obj->lid);
+							$resqlupdate = $this->db->query($sqlupdate);
+							if ($resqlupdate) {
+								$contractlineprocessed[$obj->lid]=$object->ref;
+
+								$actioncode = 'RENEW_CONTRACT';
+								$now = dol_now();
+
+								// Create an event
+								$actioncomm = new ActionComm($this->db);
+								$actioncomm->type_code    = 'AC_OTH_AUTO';		// Type of event ('AC_OTH', 'AC_OTH_AUTO', 'AC_XXX'...)
+								$actioncomm->code         = 'AC_'.$actioncode;
+								$actioncomm->label        = $label;
+								$actioncomm->datep        = $now;
+								$actioncomm->datef        = $now;
+								$actioncomm->percentage   = -1;   // Not applicable
+								$actioncomm->socid        = $object->thirdparty->id;
+								$actioncomm->authorid     = $user->id;   // User saving action
+								$actioncomm->userownerid  = $user->id;	// Owner of action
+								$actioncomm->fk_element   = $object->id;
+								$actioncomm->elementtype  = 'contract';
+								$actioncomm->note_private = $comment;
+
+								$ret = $actioncomm->create($user);       // User creating action
+							} else {
+								$contracterror[$object->id]=$object->ref;
+
+								$error++;
+								$errorforlocaltransaction++;
+								$this->error = $this->db->lasterror();
+							}
+
+							if (! $errorforlocaltransaction) {
+								$this->db->commit();
+							} else {
+								$this->db->rollback();
+							}
+						} else {
+							$error++;
+							$this->error = "Bad value for newdate in doAutoRenewContracts - expirationdate=".$expirationdate." enddatetoscan=".$enddatetoscan." duration_value=".$duration_value." duration_unit=".$duration_value;
+							dol_syslog($this->error, LOG_ERR);
+						}
+					}
+				}
+				$i++;
+			}
+		} else {
+			$error++;
+			$this->error = $this->db->lasterror();
+		}
+
+		$this->output .= count($contractlineprocessed).' contract line(s) with end date before '.dol_print_date($enddatetoscan, 'day').' were renewed'.(count($contractlineprocessed)>0 ? ' : '.join(',', $contractlineprocessed) : '');
+
+		return ($error ? 1: 0);
+	}
 }