add support for named timezones

lib/sql-string.js

 'use strict';
 
 /* jshint -W110 */
-var moment = require('moment')
+var moment = require('moment-timezone')
   , isArrayBufferView
   , SqlString = exports;
 
@@ -165,7 +165,11 @@ SqlString.formatNamedParameters = function(sql, values, timeZone, dialect) {
 };
 
 SqlString.dateToString = function(date, timeZone, dialect) {
-  date = moment(date).utcOffset(timeZone);
+  if (moment.tz.zone(timeZone)) {
+    date = moment(date).tz(timeZone);
+  } else {
+    date = moment(date).utcOffset(timeZone);
+  }
 
   if (dialect === 'mysql' || dialect === 'mariadb') {
     return date.format('YYYY-MM-DD HH:mm:ss');
@@ -200,4 +204,4 @@ SqlString.objectToValues = function(object, timeZone) {
   }
 
   return values.join(', ');
-};
\ No newline at end of file
+};

package.json

@@ -38,6 +38,7 @@
     "inflection": "^1.6.0",
     "lodash": "^3.5.0",
     "moment": "^2.9.0",
+    "moment-timezone": "^0.3.1",
     "node-uuid": "~1.4.1",
     "toposort-class": "~0.3.0",
     "validator": "^3.34.0"

test/integration/timezone.test.js

@@ -15,6 +15,9 @@ if (dialect !== 'sqlite') {
       this.sequelizeWithTimezone = Support.createSequelizeInstance({
         timezone: '+07:00'
       });
+      this.sequelizeWithNamedTimezone = Support.createSequelizeInstance({
+        timezone: 'America/New_York'
+      });
     });
 
     it('returns the same value for current timestamp', function() {
@@ -52,6 +55,21 @@ if (dialect !== 'sqlite') {
           expect(normalUser.createdAt.getTime() - this.timezonedUser.createdAt.getTime()).to.be.closeTo(60 * 60 * 7 * 1000, 50);
         });
       });
+
+      it('handles named timezones', function() {
+        var NormalUser = this.sequelize.define('user', {})
+          , TimezonedUser = this.sequelizeWithNamedTimezone.define('user', {});
+
+        return this.sequelize.sync({ force: true }).bind(this).then(function() {
+          return TimezonedUser.create({});
+        }).then(function(timezonedUser) {
+          this.timezonedUser = timezonedUser;
+          return NormalUser.find(timezonedUser.id);
+        }).then(function(normalUser) {
+          // Expect 7 hours difference, in milliseconds, +/- 1 hour for DST
+          expect(normalUser.createdAt.getTime() - this.timezonedUser.createdAt.getTime()).to.be.closeTo(60 * 60 * 4 * 1000 * -1, 60 * 60 * 1000);
+        });
+      });
     }
   });
 }