All notable changes to this project will be documented in this file.
This project adheres to [Semantic Versioning].
This change log follows the format documented in [Keep a CHANGELOG].
[semantic versioning]: http://semver.org/
[keep a changelog]: http://keepachangelog.com/
## v2.21.1 - 2021-04-15
Thanks to [Sasha Koss](http://github.com/kossnocorp) for working on the release.
### Fixed
- [Fixed a breaking change introduced by using modern default argument value syntax (see https://github.com/Hacker0x01/react-datepicker/issues/2870).](https://github.com/date-fns/date-fns/pull/2423)
## v2.21.0 - 2021-04-14
This release is brought to you by [Aleksei Korzun](http://github.com/a-korzun), [Tan75](http://github.com/tan75), [Rubens Mariuzzo](http://github.com/rmariuzzo), [Christoph Stenglein](http://github.com/cstenglein) and [Clément Tamisier](http://github.com/ctamisier).
### Fixed
- [Made `formatDistanceStrict` return `12 months` instead of `1 year` when `unit: 'month'`.](https://github.com/date-fns/date-fns/pull/2411)
- [Added Austrian German (`de-AT`) locale.](https://github.com/date-fns/date-fns/pull/2362)
## v2.20.3 - 2021-04-13
Kudos to [fturmel](http://github.com/fturmel) for working on the release.
### Fixed
- [Fixed broken tree-shaking caused by missing links to corresponding ESM.](https://github.com/date-fns/date-fns/pull/2339) ([#2207](https://github.com/date-fns/date-fns/issues/2207))
## v2.20.2 - 2021-04-12
Kudos to [Maxim Topciu](http://github.com/maximtop) for working on the release.
### Fixed
- [Fixed IE11 incompatibility caused by the usage of spread syntax.](https://github.com/date-fns/date-fns/pull/2407) ([#2408](https://github.com/date-fns/date-fns/issues/2408))
## v2.20.1 - 2021-04-09
This release is brought to you by [Sasha Koss](http://github.com/kossnocorp) and [Tan75](http://github.com/tan75).
### Fixed
- Fixed `isDate` Flow typings that we broke in `v2.20.0`.
## v2.20.0 - 2021-04-08
This release is brought to you by [Sasha Koss](http://github.com/kossnocorp), [Maxim Topciu](http://github.com/maximtop), [tu4mo](http://github.com/tu4mo), [Tan75](http://github.com/tan75), [Ardit Dine](http://github.com/arditdine), [Carl Rosell](http://github.com/CarlRosell), [Roman Mahotskyi](http://github.com/enheit), [Mateusz Krzak](http://github.com/mateuszkrzak), [fgottschalk](http://github.com/fgottschalk), [Anastasia Kobzar](http://github.com/rikkalo), [Bilguun Ochirbat](http://github.com/bilguun0203), [Lesha Koss](http://github.com/leshakoss), [YuLe](http://github.com/yuler) and [guyroberts21](http://github.com/guyroberts21).
### Fixed
- [Made `formatDistanceStrict` and `formatDistanceToNowStrict` always return `1 year` instead of `12 months`.](https://github.com/date-fns/date-fns/pull/2391) ([#2388](https://github.com/date-fns/date-fns/issues/2388))
- Fixed `nextDay`, `nextMonday` and `nextTuesday` missing in exports and type definitions. ([#2325](https://github.com/date-fns/date-fns/issues/2325))
- [Fixed a DST bug in `formatDistanceStrict`.](https://github.com/date-fns/date-fns/pull/2329) ([#2307](https://github.com/date-fns/date-fns/issues/2307))
### Added
- [Added new `eachMinuteOfInterval` function.](https://github.com/date-fns/date-fns/pull/2382)
- [Assigned the correct `firstWeekContainsDate` value (`4`) for the French locale.](https://github.com/date-fns/date-fns/pull/2273) ([#2148](https://github.com/date-fns/date-fns/issues/2148))
- [Fixed torsdag abbreviation in the Swedish locale.](https://github.com/date-fns/date-fns/pull/2220)
- [Fixed a bug in `differenceInMonths` and `intervalToDuration` that occurs when dealing with the 28th of February.](https://github.com/date-fns/date-fns/pull/2256) ([#2255](https://github.com/date-fns/date-fns/issues/2255))
### Added
- [Added new functions: `nextDay`, `nextMonday` and `nextTuesday` that allows getting the next day of the week, Monday or Tuesday respectively.](https://github.com/date-fns/date-fns/pull/2214)
## v2.18.0 - 2021-03-01
Thanks to [Tan75](http://github.com/tan75) and [Lesha Koss](http://github.com/leshakoss).
### Fixed
- [Fixed documentation missing for `intlFormat`.](https://github.com/date-fns/date-fns/pull/2259) ([#2258](https://github.com/date-fns/date-fns/issues/2258))
- [Fixed date formats in the Latvian locale.](https://github.com/date-fns/date-fns/pull/2205) ([#2202](https://github.com/date-fns/date-fns/issues/2202))
### Added
- [Added support of positive and negative offsets in `parseJSON`.](https://github.com/date-fns/date-fns/pull/2200) ([#2149](https://github.com/date-fns/date-fns/issues/2149))
## [2.17.0] - 2021-02-05
Kudos to [@shaykav](https://github.com/date-fns/date-fns/pull/1952), [@davidgape89](https://github.com/davidgape89), [@rikkalo](https://github.com/rikkalo), [@tan75](https://github.com/tan75), [@talgautb](https://github.com/talgautb), [@owenl131](https://github.com/owenl131), [@kylesezhi](https://github.com/kylesezhi), [@inigoiparragirre](https://github.com/inigoiparragirre), [@gius](https://github.com/gius), [@Endeauvirr](https://github.com/Endeauvirr) and [@frankyston](https://github.com/frankyston).
- [Fixed `differenceInMonths` for edge cases, such as the end of February dates](https://github.com/date-fns/date-fns/pull/2185).
- [Fixed suffixes for the Kazakh locale](https://github.com/date-fns/date-fns/pull/2010).
- [Fixed `formatDuration` week translation in `pt` and `pt-BR` locales](https://github.com/date-fns/date-fns/pull/2125).
- [Made Japanese locale to use the correct value for the start of the week](https://github.com/date-fns/date-fns/pull/2099).
- [Adjusted date formats in the Basque locale](https://github.com/date-fns/date-fns/pull/2080).
- [Fixed the short and medium date formats in the Czech locale](https://github.com/date-fns/date-fns/pull/2111).
- [Adjusted the Polish translations of `formatDistance`](https://github.com/date-fns/date-fns/pull/2187).
- [Fixed the week's abbreviations in the Brazilian Portuguese](https://github.com/date-fns/date-fns/pull/2170).
### Added
- [Added `intlFormat`](https://github.com/date-fns/date-fns/pull/2172) a lightweight formatting function that uses [Intl API](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl). Eventually, it will become the default formatting function, so it's highly recommended for new code.
- [Added an ability to format lowercase am/pm with `aaa` and `bbb` tokens](https://github.com/date-fns/date-fns/pull/2016).
- [Added ordinal formatting for Japanese year values](https://github.com/date-fns/date-fns/pull/2177/files).
## [2.16.1] - 2020-07-31
Kudos to [@aleksaps](https://github.com/aleksaps), [@leedriscoll](https://github.com/leedriscoll) and [@BanForFun](https://github.com/BanForFun) for pull-requests!
### Fixed
- [Fixed a typo in Scottish Gaelic (gd) locale](https://github.com/date-fns/date-fns/pull/1925).
- [Fixed typos in Serbian Latin locale](https://github.com/date-fns/date-fns/pull/1928).
- [Fixed greek grammar for Saturday on `formatRelative`](https://github.com/date-fns/date-fns/pull/1930).
- Removed locale snapshots from the npm package making it lighter.
## [2.16.0] - 2020-08-27
Kudos to [@jvpelt](https://github.com/jvpelt), [@piotrl](https://github.com/piotrl), [@yotamofek](https://github.com/yotamofek), [@dwaxweiler](https://github.com/dwaxweiler), [@leedriscoll](https://github.com/leedriscoll) and [@bradevans](https://github.com/bradevans) for working on the release. Also thanks to [@PascalHonegger](https://github.com/PascalHonegger), [@pickfire](https://github.com/pickfire), [@TheJaredWilcurt](https://github.com/TheJaredWilcurt), [@SidKH](https://github.com/SidKH) and [@nfantone](https://github.com/nfantone) for improving the documentation.
### Fixed
- [Added correct translations for Welsh `1 minute` and `2 days`](https://github.com/date-fns/date-fns/pull/1903).
- [Fixed `formatRFC3339` formatting timezone offset with minutes](https://github.com/date-fns/date-fns/pull/1890).
- [Added missing locale type definition for `formatDuration`](https://github.com/date-fns/date-fns/pull/1881)
Thanks to [@belgamo](https://github.com/belgamo), [@Matsuuu](https://github.com/Matsuuu), [@Imballinst](https://github.com/Imballinst), [@arsnyder16](https://github.com/arsnyder16), [@pankajupadhyay29](https://github.com/pankajupadhyay29), [@DCBN](https://github.com/DCBN), [@leedriscoll](https://github.com/leedriscoll), [@gottsohn](https://github.com/gottsohn), [@mukuljainx](https://github.com/mukuljainx) and [@dtriana](https://github.com/dtriana) for working on the release. Also kudos to [@KidkArolis](https://github.com/KidkArolis), [@imgx64](https://github.com/imgx64), [@fjc0k](https://github.com/fjc0k), [@wmonk](https://github.com/wmonk), [@djD-REK](https://github.com/djD-REK), [@dandv](https://github.com/dandv), [@psimk](https://github.com/psimk) and [@brimworks](https://github.com/brimworks) for improving the documentation.
### Fixed
- [Fixed behavior of `addBusinessDays` when input date is a weekend day](https://github.com/date-fns/date-fns/pull/1790).
- [Fixed `parseISO` not returning `Invalid Date` on incorrect string when there are spaces in it](https://github.com/date-fns/date-fns/pull/1791).
- [Fixed `es` round-tripping dates with Wednesday](https://github.com/date-fns/date-fns/pull/1792).
- [Fixed round-trip bug with `d`/`EEEE` ordering in tokens like `PPPPP`](https://github.com/date-fns/date-fns/pull/1795).
- [Fixed issues with parsing values in Japanese](https://github.com/date-fns/date-fns/pull/1807).
Kudos to [@julamb](https://github.com/julamb), [@JacobSoderblom](https://github.com/JacobSoderblom), [@justingrant](http://github.com/justingrant), [@dragunoff](https://github.com/dragunoff), [@jmate0321](https://github.com/jmate0321), [@gbhasha](https://github.com/gbhasha), [@rasck](https://github.com/rasck), [@AlbertoPdRF](https://github.com/AlbertoPdRF), [@sebastianhaberey](https://github.com/sebastianhaberey) and [@giogonzo](https://github.com/giogonzo) for working on the release!
### Fixed
- [Fixed DST issues with `add`, `addDays` and `addMonths`](https://github.com/date-fns/date-fns/pull/1760).
- [Fixed "quarter" translation in the Bulgarian locale](https://github.com/date-fns/date-fns/pull/1763).
- [Fixed `formatDistance` strings in the Hungarian locale](https://github.com/date-fns/date-fns/pull/1765).
Thanks to [@JorenVos](https://github.com/JorenVos), [@developergouli](https://github.com/developergouli), [@rhlowe](https://github.com/rhlowe) and [@justingrant](http://github.com/justingrant) for working on the release!
### Fixed
- [Fixed mei abbreviation in the Dutch locale](https://github.com/date-fns/date-fns/pull/1752).
- [Fixed `differenceInDays` DST behavior broken in 2.12.0](https://github.com/date-fns/date-fns/pull/1754).
Kudos to [@leshakoss](http://github.com/leshakoss), [@skyuplam](https://github.com/skyuplam), [@so99ynoodles](https://github.com/so99ynoodles), [@dkozickis](https://github.com/dkozickis), [@belgamo](https://github.com/belgamo), [@akgondber](https://github.com/akgondber), [@dcousens](https://github.com/dcousens) and [@BoomDev](https://github.com/BoomDev) for working on the release!
### Fixed
- [Fixed minulý štvrtok in Slovak locale](https://github.com/date-fns/date-fns/pull/1701).
- Fixed date ordinalNumber for [ja/zh-CN/zh-TW](https://github.com/date-fns/date-fns/pull/1690) and [ko](https://github.com/date-fns/date-fns/pull/1696).
- [Added new function `formatDistanceToNowStrict`](https://github.com/date-fns/date-fns/pull/1679).
## [2.11.1] - 2020-03-26
### Fixed
- Rebuilt TypeScript and flow types.
## [2.11.0] - 2020-03-13
Kudos to [@oakhan3](https://github.com/oakhan3), [@Mukhammadali](https://github.com/Mukhammadali), [@altrim](https://github.com/altrim), [@leepowellcouk](https://github.com/leepowellcouk), [@amatzon](@https://github.com/amatzon), [@bryanMt](https://github.com/bryanMt), [@kalekseev](https://github.com/kalekseev), [@eugene-platov](https://github.com/eugene-platov) and [@tjrobinson](https://github.com/tjrobinson) for working on the release.
### Fixed
- [Fixed a bug in `differenceInYears` causing incorrect results when the left date is a leap day](https://github.com/date-fns/date-fns/pull/1654).
- [Fixed `parseISO` to work correctly around time shift dates](https://github.com/date-fns/date-fns/pull/1667).
- [Fixed `format` to work correctly with GMT-0752/GMT-0456 and similar timezones](https://github.com/date-fns/date-fns/pull/1666).
### Changed
- [Changed `getDay` typings to return `0|1|2|3|4|5|6` instead of `number`](https://github.com/date-fns/date-fns/pull/1668).
- [Improved Chinese locale](https://github.com/date-fns/date-fns/pull/1664):
- Change date format to meet the national standard (GB/T 7408-2005).
- Improve `ordinalNumber` function behavior.
- Add prefix in `formatRelative` depending on if it's a current week or not.
### Added
- [Added Uzbek `uz` locale](https://github.com/date-fns/date-fns/pull/1648).
- [Updated Macedonian locale for v2](https://github.com/date-fns/date-fns/pull/1649).
- [Fixed `formatISO` when formatting time with timezones with minute offsets > 0](https://github.com/date-fns/date-fns/pull/1599). Kudos to [@dcRUSTy](https://github.com/dcRUSTy).
### Fixed
- Fixed a bug in setDay when using weekStartsOn that is not 0
### Added
- [Added `weeks` to `Duration`](https://github.com/date-fns/date-fns/pull/1592).
- [Added `weeks` support to `add` and `sub`](https://github.com/date-fns/date-fns/pull/1592).
- [Added details message in `throwProtectedError`](https://github.com/date-fns/date-fns/pull/1592).
## [2.9.0] - 2020-01-08
Thanks to [@mborgbrant](https://github.com/mborgbrant), [@saintplay](https://github.com/saintplay), [@mrenty](https://github.com/mrenty), [@kibertoad](https://github.com/kibertoad), [@levibuzolic](https://github.com/levibuzolic), [@Anshuman71](https://github.com/Anshuman71), [@talgautb](https://github.com/talgautb), [@filipjuza](https://github.com/filipjuza), [@tobyzerner](https://github.com/tobyzerner), [@emil9453](https://github.com/emil9453), [@fintara](https://github.com/fintara), [@pascaliske](https://github.com/pascaliske), [@rramiachraf](https://github.com/rramiachraf), [@marnusw](https://github.com/marnusw) and [@Imballinst](https://github.com/Imballinst) for working on the release.
### Fixed
- [Fixed a bug with addBusinessDays returning the Tuesday when adding 1 day on weekends. Now it returns the Monday](https://github.com/date-fns/date-fns/pull/1588).
- [Added missing timezone to `formatISO`](https://github.com/date-fns/date-fns/pull/1576).
- [Removed dots from short day period names in the Kazakh locale](https://github.com/date-fns/date-fns/pull/1512).
- [Fixed typo in formatDistance in the Czech locale](https://github.com/date-fns/date-fns/pull/1540).
- [Fixed shortenings in the Bulgarian locale](https://github.com/date-fns/date-fns/pull/1560).
- [Fixed regex for the May in the Portuguese locale](https://github.com/date-fns/date-fns/pull/1565).
### Added
- [Added `eachMonthOfInterval` and `eachYearOfInterval`](https://github.com/date-fns/date-fns/pull/618).
- [Added `inclusive` option to `areIntervalsOverlapping](https://github.com/date-fns/date-fns/pull/643).
- [Added `isExists` function that checks if the given date is exists](https://github.com/date-fns/date-fns/pull/682).
- [Added `add` function to add seconds, minutes, hours, weeks, years in single call](https://github.com/date-fns/date-fns/pull/1581).
- [Added `sub` function, the opposite of `add`](https://github.com/date-fns/date-fns/pull/1583).
- [Added `Duration` type used in `add` and `sub`](https://github.com/date-fns/date-fns/pull/1583).
- [Reduced the total minified build size by 1Kb/4%](https://github.com/date-fns/date-fns/pull/1563).
- [Made all properties in `Locale` type optional](https://github.com/date-fns/date-fns/pull/1542).
- [Added missing properties to `Locale` type](https://github.com/date-fns/date-fns/pull/1542).
- [Add the locale code to `Locale` type](https://github.com/date-fns/date-fns/pull/1580).
- [Added support of space time separator to `parseJSON`](https://github.com/date-fns/date-fns/pull/1579).
- [Allowed up to 7 digits in milliseconds in `parseJSON`](https://github.com/date-fns/date-fns/pull/1579).
## [2.8.1] - 2019-11-22
Thanks to [@Imballinst](https://github.com/Imballinst) for the bug fix!
### Fixed
- [Add colon between the hour and minutes for `formatRFC3339`](https://github.com/date-fns/date-fns/pull/1549). [See #1548](https://github.com/date-fns/date-fns/issues/1548).
## [2.8.0] - 2019-11-19
Kudos to [@NaridaL](https://github.com/NaridaL), [@Zyten](https://github.com/Zyten), [@Imballinst](https://github.com/Imballinst), [@leshakoss](https://github.com/leshakoss) and [@Neorth](https://github.com/Neorth) for working on the release.
### Fixed
- [Remove the next week preposition in the Swedish locale](https://github.com/date-fns/date-fns/pull/1538).
- [Added `formatISO`, `formatISO9075`, `formatRFC3339`, and `formatRFC7231` functions](https://github.com/date-fns/date-fns/pull/1536).
## [2.7.0] - 2019-11-07
Thanks to [@mzgajner](https://github.com/mzgajner), [@NaridaL](https://github.com/NaridaL), [@Zyten](https://github.com/Zyten), [@leshakoss](https://github.com/leshakoss), [@fintara](https://github.com/fintara), [@kpr-hellofresh](https://github.com/kpr-hellofresh) for contributing to the release.
### Fixed
- [Fixed a mistake in the Slovenian locale](https://github.com/date-fns/date-fns/pull/1529).
- [Fixed incorrect behavior of `parseISO` in Firefox caused by differences in `getTimezoneOffset`](https://github.com/date-fns/date-fns/pull/1495).
### Changed
- [Make object arguments types more elaborate in Flow type definitions](https://github.com/date-fns/date-fns/pull/1519).
- [Get rid of deprecated Function in Flow type definitions](https://github.com/date-fns/date-fns/pull/1520).
- [Allow `parseJSON` to accept strings without trailing 'Z' symbol and with up to 6 digits in the milliseconds' field](https://github.com/date-fns/date-fns/pull/1499).
### Added
- [Added Bulgarian (bg) locale](https://github.com/date-fns/date-fns/pull/1522).
## [2.6.0] - 2019-10-22
Kudos to [@marnusw](https://github.com/marnusw), [@cdrikd](https://github.com/cdrikd) and [@rogyvoje](https://github.com/rogyvoje) for working on the release!
### Added
- [Added `parseJSON` - lightweight function (just 411 B) that parses dates formatted with `toJSON`](https://github.com/date-fns/date-fns/pull/1463).
- [Added the language code to each locale](https://github.com/date-fns/date-fns/pull/1489).
- [Added both Serbian - cyrillic (sr) and latin (sr-Latn) locales](https://github.com/date-fns/date-fns/pull/1494).
## [2.5.1] - 2019-10-18
Thanks to [@mitchellbutler](https://github.com/mitchellbutler) for the bug fix!
### Fixed
- [Fixed infinite loop in `addBusinessDays`](https://github.com/date-fns/date-fns/pull/1486).
## [2.5.0] - 2019-10-16
Kudos to [@dkozickis](https://github.com/dkozickis), [@drugoi](https://github.com/drugoi), [@kranthilakum](https://github.com/kranthilakum), [@102](https://github.com/102), [@gpetrioli](https://github.com/gpetrioli) and [@JulienMalige](https://github.com/JulienMalige) for making the release happen.
### Fixed
- [Fixed compatibility with IE11 by removing `findIndex` from the code](https://github.com/date-fns/date-fns/pull/1457).
This release brought to you by these amazing people: [@lovelovedokidoki](https://github.com/lovelovedokidoki), [@alexigityan](https://github.com/alexigityan), [@kalekseev](https://github.com/kalekseev) and [@andybangs](https://github.com/andybangs). You rock!
- [Fixed offset for Eastern Hemisphere in `parseISO`](https://github.com/date-fns/date-fns/pull/1450).
### Added
- [Added Armenian locale support](https://github.com/date-fns/date-fns/pull/1448).
## [2.3.0] - 2019-09-24
Huge thanks to [@lovelovedokidoki](https://github.com/lovelovedokidoki) who improved 8 (!) locales in an unstoppable open-source rampage and [@VesterDe](https://github.com/VesterDe) for fixing Slovenian locale 👏
### Fixed
- [Fixed the translation of "yesterday" in the Slovenian locale](https://github.com/date-fns/date-fns/pull/1420).
- [Fixed French parsing issues with June and August](https://github.com/date-fns/date-fns/pull/1430).
- [Accept abbreviated March, June, July in Norwegian locales](https://github.com/date-fns/date-fns/pull/1431).
- [Added parsing for Greek months with long formatting](https://github.com/date-fns/date-fns/pull/1435).
## [2.2.1] - 2019-09-12
Kudos to date-fns contributors: [@mzgajner](https://github.com/mzgajner), [@sibiraj-s](https://github.com/sibiraj-s), [@mukeshmandiwal](https://github.com/mukeshmandiwal), [@SneakyFish5](https://github.com/SneakyFish5) and [@CarterLi](https://github.com/CarterLi).
### Added
- [Added new `set` function](https://github.com/date-fns/date-fns/pull/1398).
- [Updated Slovenian (sl) locale for v2](https://github.com/date-fns/date-fns/pull/1418).
- [Added Tamil (ta) locale](https://github.com/date-fns/date-fns/pull/1411).
- [Added Hindi (hi) locale](https://github.com/date-fns/date-fns/pull/1409).
- [Added support of `\n` in `format`, `lightFormat` and `parse`](https://github.com/date-fns/date-fns/pull/1417).
Thanks to date-fns contributors: [@ManadayM](https://github.com/ManadayM), [@illuminist](https://github.com/illuminist), [@visualfanatic](https://github.com/visualfanatic), [@vsaarinen](https://github.com/vsaarinen) and at least but not least [@leshakoss](https://github.com/leshakoss)!
- [Fix](https://github.com/date-fns/date-fns/pull/1046) `getWeekOfMonth` with `options.weekStartsOn` set to 1 [not working for Sundays](https://github.com/date-fns/date-fns/issues/1040). Kudos to [@waseemahmad31](https://github.com/waseemahmad31)!
## [2.0.0] - 2019-08-20
If you're upgrading from v2 alpha or beta, [see the pre-release changelog](https://gist.github.com/kossnocorp/a307a464760b405bb78ef5020a4ab136).
See PR [#789](https://github.com/date-fns/date-fns/pull/789).
- [Fixed DST issue](https://github.com/date-fns/date-fns/pull/1003). See [#972](https://github.com/date-fns/date-fns/issues/972) and [#992](https://github.com/date-fns/date-fns/issues/992) for more details.
- Fixed DST issue in `eachDayOfInterval` that caused time in the days
- **BREAKING**: now functions don't accept string arguments, but only
numbers or dates. When a string is passed, it will result in
an unexpected result (`Invalid Date`, `NaN`, etc).
From now on a string should be parsed using `parseISO` (ISO 8601)
or `parse`.
In v1 we've used `new Date()` to parse strings, but it resulted in many
hard-to-track bugs caused by inconsistencies in different browsers.
To address that we've implemented our ISO 8601 parser but that made
library to significantly grow in size. To prevent inevitable bugs
and keep the library tiny, we made this trade-off.
See [this post](https://blog.date-fns.org/post/we-cut-date-fns-v2-minimal-build-size-down-to-300-bytes-and-now-its-the-smallest-date-library-18f2nvh2z0yal) for more details.
```javascript
// Before v2.0.0
addDays('2016-01-01', 1)
// v2.0.0 onward
addDays(parseISO('2016-01-01'), 1)
```
- **BREAKING**: new format string API for `format` function
which is based on [Unicode Technical Standard #35](https://www.unicode.org/reports/tr35/tr35-dates.html#Date_Field_Symbol_Table).
See [this post](https://blog.date-fns.org/post/unicode-tokens-in-date-fns-v2-sreatyki91jg) for more details.
| Unit | v2 Pattern | v1 Pattern | Result examples |
//=> ['1 januaro 2022', '11 februaro 2022', '2 julio 2022']
```
- Added support for [ECMAScript Modules](http://www.ecma-international.org/ecma-262/6.0/#sec-modules).
It allows usage with bundlers that support tree-shaking,
like [rollup.js](http://rollupjs.org) and [webpack](https://webpack.js.org):
```javascript
// Without tree-shaking:
import format from 'date-fns/format'
import parse from 'date-fns/parse'
// With tree-shaking:
import { format, parse } from 'date-fns'
```
Also, ESM functions provide default export, they can be used with TypeScript
to import functions in more idiomatic way:
```typescript
// Before
import * as format from 'date-fns/format'
// Now
import format from 'date-fns/format'
```
- `formatRelative` function. See [formatRelative](https://date-fns.org/docs/formatRelative)
- Flow typings for `index.js`, `fp/index.js`, `locale/index.js`, and their ESM equivalents.
See PR [#558](https://github.com/date-fns/date-fns/pull/558)
- New locale-dependent week-numbering year helpers:
- `getWeek`
- `getWeekYear`
- `setWeek`
- `setWeekYear`
- `startOfWeekYear`
- Added `eachWeekOfInterval`, the weekly equivalent of `eachDayOfInterval`
- [Added `getUnixTime` function](https://github.com/date-fns/date-fns/pull/870). Kudos to [@Kingwl](https://github.com/Kingwl).
- [New decade helpers](https://github.com/date-fns/date-fns/pull/839). Thanks to [@y-nk](https://github.com/y-nk)!
- `getDecade`
- `startOfDecade`
- `endOfDecade`
- `lastDayOfDecade`
- [New `roundToNearestMinutes` function](https://github.com/date-fns/date-fns/pull/928). Kudos to [@xkizer](https://github.com/xkizer).
- Added new function `fromUnixTime`. Thansk to [@xkizer](https://github.com/xkizer).
- New interval, month, and year helpers to fetch a list of all Saturdays and Sundays (weekends) for a given date interval. `eachWeekendOfInterval` is the handler function while the other two are wrapper functions. Kudos to [@laekettavong](https://github.com/laekettavong)!
- `eachWeekendOfInterval`
- `eachWeekendOfMonth`
- `eachWeekendOfYear`
- Build-efficient `lightFormat` that only supports the popular subset of tokens. See [#1050](https://github.com/date-fns/date-fns/pull/1015).
- `parseISO` function that parses ISO 8601 strings. See [#1023](https://github.com/date-fns/date-fns/pull/1023).
- Add constants that can be imported directly from `date-fns` or the submodule `date-fns/constants`:
similar to `addDays` but ignoring weekends. Thanks to [@ThorrStevens](https://github.com/ThorrStevens)!
## [1.30.1] - 2018-12-10
### Fixed
- [Fixed DST issue](https://github.com/date-fns/date-fns/pull/1005). See [#972](https://github.com/date-fns/date-fns/issues/972) and [#992](https://github.com/date-fns/date-fns/issues/992) for more details. This fix was backported from v2.
- Fix a few bugs that appear in timezones with offsets that include seconds (e.g. GMT+00:57:44). See PR [#789](https://github.com/date-fns/date-fns/issues/789). This fix was backported from v2.
- [Fix misspelled January in the Thai locale](https://github.com/date-fns/date-fns/pull/913). Thanks to [@ratchapol-an](https://github.com/ratchapol-an)!
- Fix Italian translations for `formatDistance`. ([see the issue: #550](https://github.com/date-fns/date-fns/issues/550); [see the PR: #552](https://github.com/date-fns/date-fns/pull/552))
