use moment to detect timezones

setup/sql/upgrade-00006.sql

@@ -0,0 +1,16 @@
+# Header section
+# Define incrementing schema version number
+SET @schema_version = '6';
+
+# Creates table to store timezone offsets required to calculate correct start time for sending
+# messages to specific subscribers
+CREATE TABLE `tzoffset` (
+  `tz` varchar(100) CHARACTER SET ascii NOT NULL DEFAULT '',
+  `offset` int(11) NOT NULL DEFAULT '0',
+  PRIMARY KEY (`tz`)
+) ENGINE=InnoDB DEFAULT CHARSET=ascii;
+
+# Footer section
+LOCK TABLES `settings` WRITE;
+INSERT INTO `settings` (`key`, `value`) VALUES('db_schema_version', @schema_version) ON DUPLICATE KEY UPDATE `value`=@schema_version;
+UNLOCK TABLES;