Merge pull request #1 from egarkavy/fix-timezones

fix(jkbrzt#391): timezones

README.md

@@ -217,7 +217,7 @@ For more examples see
 
 Optionally, it also supports use of the `TZID` parameter in the
 [RFC](https://tools.ietf.org/html/rfc5545#section-3.2.19)
-when the [Luxon](https://github.com/moment/luxon) library is provided. The 
+when the [Luxon](https://github.com/moment/luxon) library is provided. The
 [specification](https://moment.github.io/luxon/docs/manual/zones.html#specifying-a-zone)
 and [support matrix](https://moment.github.io/luxon/docs/manual/matrix.html) for Luxon apply.
 
@@ -230,9 +230,9 @@ new RRule({
   tzid: 'Asia/Tokyo'
 }).all()
 
-// assuming the system timezone is set to America/Los_Angeles, you get:
-[ '2018-01-31T17:30:00.000Z' ]
-// which is the time in Los Angeles when it's 2018-02-01T10:30:00 in Tokyo.
+// regardless of the system timezone, you get:
+[ '2018-02-01T01:30:00.000Z' ]
+// which is the time in UTC when it's 2018-02-01T10:30:00 in Tokyo.
 ```
 
 Whether or not you use the `TZID` param, make sure to only use JS `Date` objects that are
@@ -243,19 +243,22 @@ represented in UTC to avoid unexpected timezone offsets being applied, for examp
 new RRule({
   freq: RRule.MONTHLY,
   dtstart: new Date(2018, 1, 1, 10, 30),
-  until: new Date(2018, 2, 31)
+  until: new Date(2018, 2, 31),
+  tzid: 'Asia/Tokyo'
 }).all()
 
-[ '2018-02-01T18:30:00.000Z', '2018-03-01T18:30:00.000Z' ]
+// assuming your local timezone is Asia/Tokyo
+[ '2018-01-31T16:30:00.000Z', '2018-02-28T16:30:00.000Z' ]
 
 // RIGHT: Will produce dates with recurrences at the correct time
 new RRule({
   freq: RRule.MONTHLY,
   dtstart: new Date(Date.UTC(2018, 1, 1, 10, 30)),
-  until: new Date(Date.UTC(2018, 2, 31))
+  until: new Date(Date.UTC(2018, 2, 31)),
+  tzid: 'Asia/Tokyo'
 }).all()
 
-[ '2018-02-01T10:30:00.000Z', '2018-03-01T10:30:00.000Z' ]
+[ '2018-02-01T01:30:00.000Z', '2018-03-01T01:30:00.000Z' ]
 ```
 
 ### API
@@ -824,4 +827,3 @@ more details.
 #### Related projects
 
 * https://rrules.com/ — RESTful API to get back occurrences of RRULEs that conform to RFC 5545.
-

package.json

@@ -28,7 +28,11 @@
     "build": "yarn lint && tsc && webpack && tsc dist/esm/**/*.d.ts",
     "lint": "yarn tslint --project . --fix --config tslint.json",
     "test": "TS_NODE_PROJECT=tsconfig.test.json mocha **/*.test.ts",
-    "test-ci": "TS_NODE_PROJECT=tsconfig.test.json nyc mocha **/*.test.ts"
+    "test-ci": "TS_NODE_PROJECT=tsconfig.test.json nyc mocha **/*.test.ts",
+    "test:tz": "npm run test:tz1 && npm run test:tz2 && npm run test:tz3",
+    "test:tz1": "TZ=Asia/Tokyo npm t",
+    "test:tz2": "TZ=Europe/Madrid npm t",
+    "test:tz3": "TZ=America/Chicago npm t"
   },
   "nyc": {
     "extension": [

src/dateutil.ts

@@ -67,7 +67,7 @@ export namespace dateutil {
   /**
    * @return {Number} the date's timezone offset in ms
    */
-  export const tzOffset = function (date: Date) {
+  export const tzOffset = function (date: Date): number {
     return date.getTimezoneOffset() * 60 * 1000
   }
 
@@ -109,7 +109,7 @@ export namespace dateutil {
   /**
    * @return {Number} python-like weekday
    */
-  export const getWeekday = function (date: Date) {
+  export const getWeekday = function (date: Date): number {
     return PY_WEEKDAYS[date.getUTCDay()]
   }
 

src/datewithzone.ts

@@ -33,8 +33,17 @@ export class DateWithZone {
     }
 
     try {
-      const datetime = DateTime
-        .fromJSDate(this.date)
+      const { date } = this
+      const local = new Date(
+        date.getUTCFullYear(),
+        date.getUTCMonth(),
+        date.getUTCDate(),
+        date.getUTCHours(),
+        date.getUTCMinutes(),
+        date.getUTCSeconds(),
+        date.valueOf() % 1000
+      )
+      const datetime = DateTime.fromJSDate(local)
 
       const rezoned = datetime.setZone(this.tzid!, { keepLocalTime: true })
 

test/datewithzone.test.ts

@@ -37,8 +37,9 @@ describe('rezonedDate', () => {
     const currentLocalDate = DateTime.local(2000, 2, 6, 1, 0, 0)
     setMockDate(currentLocalDate.toJSDate())
 
-    const d = DateTime.fromISO('20101005T110000').toJSDate()
+    const d = DateTime.fromISO('20101005T110000Z').toJSDate()
     const dt = new DateWithZone(d, targetZone)
+
     expect(dt.rezonedDate()).to.deep.equal(
       expectedDate(DateTime.fromISO('20101005T110000'), currentLocalDate, targetZone)
     )
@@ -63,4 +64,4 @@ describe('rezonedDate', () => {
     DateTime.fromJSDate = origfromJSDate
     resetMockDate()
   })
-})
+})

test/rrule.test.ts

@@ -1,9 +1,8 @@
-import { parse, datetime, testRecurring, expectedDate } from './lib/utils'
+import { parse, datetime, testRecurring } from './lib/utils'
 import { expect } from 'chai'
 import { RRule, rrulestr, Frequency } from '../src/index'
 import { DateTime } from 'luxon'
 import { set as setMockDate, reset as resetMockDate } from 'mockdate'
-import { optionsToString } from '../src/optionstostring';
 
 describe('RRule', function () {
   // Enable additional toString() / fromString() tests
@@ -27,7 +26,7 @@ describe('RRule', function () {
     const s2 = rrulestr(s1).toString()
     expect(s1).equals(s2, s1 + ' => ' + s2)
   })
-  
+
   it('rrulestr itteration not infinite when interval 0', function () {
     ['FREQ=YEARLY;INTERVAL=0;BYSETPOS=1;BYDAY=MO',
     'FREQ=MONTHLY;INTERVAL=0;BYSETPOS=1;BYDAY=MO',
@@ -3664,12 +3663,9 @@ describe('RRule', function () {
         tzid: targetZone
       })
       const recurrence = rule.all()[0]
-      const expected = expectedDate(startDate, currentLocalDate, targetZone)
+      const expected = new Date('2013-08-06T18:00:00.000Z') // regardless in which timezone the local time is, the result in UTC must be the same!
 
-      expect(recurrence)
-        .to.deep.equal(
-          expected 
-        )
+      expect(recurrence).to.deep.equal(expected)
 
       resetMockDate()
     })
@@ -3684,12 +3680,9 @@ describe('RRule', function () {
         tzid: targetZone
       })
       const recurrence = rule.all()[0]
-      const expected = expectedDate(startDate, currentLocalDate, targetZone)
+      const expected = new Date('2013-08-06T18:00:00.000Z') // regardless in which timezone the local time is, the result in UTC must be the same!
 
-      expect(recurrence)
-        .to.deep.equal(
-          expected 
-        )
+      expect(recurrence).to.deep.equal(expected)
 
       resetMockDate()
     })
@@ -3704,11 +3697,11 @@ describe('RRule', function () {
         tzid: targetZone
       })
       const recurrence = rule.after(new Date(0))
-      const expected = expectedDate(startDate, currentLocalDate, targetZone)
+      const expected = new Date('2013-08-06T18:00:00.000Z') // regardless in which timezone the local time is, the result in UTC must be the same!
 
       expect(recurrence)
         .to.deep.equal(
-          expected 
+          expected
         )
 
       resetMockDate()

test/rruleset.test.ts

@@ -520,17 +520,17 @@ describe('RRuleSet', function () {
       set.rrule(new RRule({
         freq: RRule.YEARLY,
         count: 4,
-        dtstart: DateTime.fromISO('20000101T090000').toJSDate(),
+        dtstart: DateTime.fromISO('20000101T090000Z').toJSDate(), // always use date in UTC
         tzid: targetZone
       }))
 
       set.exdate(
-        DateTime.fromISO('20010101T090000').toJSDate(),
+        DateTime.fromISO('20010101T090000Z').toJSDate(),
       )
 
       set.rdate(
-        DateTime.fromISO('20020301T090000').toJSDate(),
-      )     
+        DateTime.fromISO('20020301T090000Z').toJSDate(),
+      )
 
       expect(set.all()).to.deep.equal([
         expectedDate(DateTime.fromISO('20000101T090000'), currentLocalDate, targetZone),
@@ -564,7 +564,7 @@ describe('RRuleSet', function () {
       set.tzid(targetZone)
 
       set.rdate(
-        DateTime.fromISO('20020301T090000').toJSDate(),
+        DateTime.fromISO('20020301T090000Z').toJSDate(),
       )
 
       expect(set.all()).to.deep.equal([
@@ -755,7 +755,7 @@ describe('RRuleSet', function () {
 
       expect(set.rrules().map(e => e.toString())).eql([rrule.toString()]);
     });
-    
+
     it('exrules()', () => {
       let set = new RRuleSet();
       let rrule = new RRule({
@@ -773,7 +773,7 @@ describe('RRuleSet', function () {
       let set = new RRuleSet();
       let dt = parse('19610201T090000');
       set.rdate(dt);
-      
+
       expect(set.rdates()).eql([dt]);
     });
 
@@ -785,4 +785,4 @@ describe('RRuleSet', function () {
       expect(set.exdates()).eql([dt]);
     });
   });
-});
+});

test/timezones.test.ts

@@ -0,0 +1,43 @@
+import { RRule } from '../src/index'
+import { expect } from "chai"
+
+const ruleByTzid = (tzid: string) => new RRule({
+  freq: RRule.WEEKLY,
+  dtstart: new Date(Date.UTC(2020, 1, 1, 0, 0, 0)), // always use UTC dates!!!
+  tzid,
+  byweekday: [RRule.TU],
+  count: 2
+})
+
+const mapToIso = (arr: Array<Date>): Array<string> =>
+  arr.map(d => d.toISOString())
+
+describe('timezones', () => {
+  it('Europe/Paris', () => {
+    const tzid = 'Europe/Paris'
+    const rule = ruleByTzid(tzid)
+    expect(rule.toString()).to.equal('DTSTART;TZID=Europe/Paris:20200201T000000\nRRULE:FREQ=WEEKLY;BYDAY=TU;COUNT=2')
+    expect(mapToIso(rule.all())).to.deep.equal([
+      '2020-02-03T23:00:00.000Z',
+      '2020-02-10T23:00:00.000Z'
+    ])
+  })
+
+  it('America/New_York', () => {
+    const rule = ruleByTzid('America/New_York')
+    expect(rule.toString()).to.equal('DTSTART;TZID=America/New_York:20200201T000000\nRRULE:FREQ=WEEKLY;BYDAY=TU;COUNT=2')
+    expect(mapToIso(rule.all())).to.deep.equal([
+      '2020-02-04T05:00:00.000Z',
+      '2020-02-11T05:00:00.000Z'
+    ])
+  })
+
+  it('UTC', () => {
+    const rule = ruleByTzid('UTC')
+    expect(rule.toString()).to.equal('DTSTART:20200201T000000Z\nRRULE:FREQ=WEEKLY;BYDAY=TU;COUNT=2')
+    expect(mapToIso(rule.all())).to.deep.equal([
+      '2020-02-04T00:00:00.000Z',
+      '2020-02-11T00:00:00.000Z'
+    ])
+  })
+})