diff -urN zabbix-2.2.6.org/frontends/php/api/classes/CMaintenance.php zabbix-2.2.6.ZBX-8884/frontends/php/api/classes/CMaintenance.php
--- zabbix-2.2.6.org/frontends/php/api/classes/CMaintenance.php	2014-08-27 22:07:26.000000000 +0900
+++ zabbix-2.2.6.ZBX-8884/frontends/php/api/classes/CMaintenance.php	2014-10-10 22:35:49.000000000 +0900
@@ -484,23 +484,33 @@
 			}
 
 			// Checking whether a maintenance with this name already exists. First, getting all maintenances with the same name as this
-			$receivedMaintenances = API::Maintenance()->get(array(
-				'filter' => array('name' => $maintenance['name'])
-			));
+			if (isset($maintenance['name'])) {
+				$receivedMaintenances = API::Maintenance()->get(array(
+					'filter' => array('name' => $maintenance['name'])
+				));
 
-			// validate if maintenance name already exists
-			foreach ($receivedMaintenances as $rMaintenance) {
-				if (bccomp($rMaintenance['maintenanceid'], $maintenance['maintenanceid']) != 0) {
-					self::exception(ZBX_API_ERROR_PARAMETERS, _s('Maintenance "%s" already exists.', $maintenance['name']));
+				// validate if maintenance name already exists
+				foreach ($receivedMaintenances as $rMaintenance) {
+					if (bccomp($rMaintenance['maintenanceid'], $maintenance['maintenanceid']) != 0) {
+						self::exception(ZBX_API_ERROR_PARAMETERS, _s('Maintenance "%s" already exists.', $maintenance['name']));
+					}
 				}
 			}
 
 			// validate maintenance active since
+			if (!isset($maintenance['active_since'])) {
+				// if not set, then existing value is assumed.
+				$maintenance['active_since'] = $updMaintenances[$maintenance['maintenanceid']]['active_since'];
+			}
 			if (!validateUnixTime($maintenance['active_since'])) {
 				self::exception(ZBX_API_ERROR_PARAMETERS, _s('"%s" must be between 1970.01.01 and 2038.01.18.', _('Active since')));
 			}
 
 			// validate maintenance active till
+			if (!isset($maintenance['active_till'])) {
+				// if not set, then existing value is assumed.
+				$maintenance['active_till'] = $updMaintenances[$maintenance['maintenanceid']]['active_till'];
+			}
 			if (!validateUnixTime($maintenance['active_till'])) {
 				self::exception(ZBX_API_ERROR_PARAMETERS, _s('"%s" must be between 1970.01.01 and 2038.01.18.', _('Active till')));
 			}
@@ -511,6 +521,10 @@
 			}
 
 			// validate timeperiods
+			if (!isset($maintenance['timeperiods'])) {
+				// if not set, then existing value is assumed.
+				$maintenance['timeperiods'] = $updMaintenances[$maintenance['maintenanceid']]['timeperiods'];
+			}
 			if (empty($maintenance['timeperiods'])) {
 				self::exception(ZBX_API_ERROR_PARAMETERS, _('At least one maintenance period must be created.'));
 			}
@@ -551,6 +565,14 @@
 			}
 		}
 
+		// if timeperiods not set, then existing value is assumed.
+		foreach ($maintenances as &$maintenance) {
+			if (!isset($maintenance['timeperiods'])) {
+				$maintenance['timeperiods'] = $updMaintenances[$maintenance['maintenanceid']]['timeperiods'];
+			}
+		}
+		unset($maintenance);
+
 		$this->removeSecondsFromTimes($maintenances);
 
 		$update = array();