Open-source date-time software
219 open-source libraries, tools and applications tagged date-time, ranked by how closely date-time is their primary purpose, then by adoption and maintenance health. Each entry links to a page with sources, use cases and when to choose or avoid it.
219 products, primary matches first, then adoption-weighted; health v2 shown.
| Product | Health v2 | Stars | Maturity |
|---|---|---|---|
| iamkun/dayjs Day.js is a minimalist JavaScript library for parsing, validating, manipulating, and displaying dates and times. It offers a Moment.js‑comp… | 94 | 48661 | active |
| date-fns date-fns is a modern JavaScript date utility library providing 200+ modular, immutable functions for parsing, formatting, and manipulating … | 90 | 36647 | stable |
| date-fns date-fns is a modern JavaScript date utility library offering over 200 pure functions for date manipulation. It works in both browser and N… | 90 | 36647 | active |
| briannesbitt/Carbon Carbon is a PHP library extending the native DateTime class with a fluent, immutable-friendly API for date and time manipulation. It suppor… | 98 | 16590 | stable |
| flatpickr/flatpickr flatpickr is a lightweight, dependency-free JavaScript datetime picker library for web forms, supporting date, time, range, and multiple-da… | 23 | 16463 | stable |
| moment/luxon Luxon is a JavaScript library for working with dates and times, providing DateTime, Duration, and Interval types with an immutable, chainab… | 72 | 16461 | stable |
| WenchaoD/FSCalendar FSCalendar is a fully customizable iOS calendar UI library written in Objective-C with Swift compatibility. It supports month/week scope sw… | 23 | 10636 | stable |
| wix/react-native-calendars A declarative, cross-platform React Native calendar component library written in pure JavaScript with no native code. It provides Calendar,… | 72 | 10315 | stable |
| arrow-py/arrow Arrow is a Python library providing a human-friendly, drop-in replacement for the datetime type with simpler creation, manipulation, format… | 61 | 9051 | stable |
| bigcalendar/react-big-calendar react-big-calendar is a React events calendar component styled like Google Calendar or Outlook, built with flexbox for modern browsers. It … | 82 | 8760 | stable |
| malcommac/SwiftDate SwiftDate is a Swift library for parsing, validating, manipulating, comparing, and formatting dates, times, and timezones across Apple plat… | 23 | 7689 | stable |
| gpbl/react-day-picker React DayPicker is a customizable date picker component library for React, supporting single, multiple, and range date selections with exte… | 98 | 6860 | stable |
| python-pendulum/pendulum Pendulum is a Python library that provides a cleaner, more intuitive API for working with dates, times, and timezones as a drop-in replacem… | 74 | 6676 | active |
| kizitonwose/Calendar A highly customizable calendar library for Android (view system via RecyclerView) and Compose Multiplatform (via LazyRow/LazyColumn). It pr… | 80 | 5615 | active |
| vercel/ms A tiny TypeScript utility for converting human-readable time strings like '2 days' to milliseconds and back. It supports many unit aliases,… | 57 | 5556 | stable |
| swiftlang/swift-corelibs-foundation The Swift Foundation project providing core utility classes, data structures, internationalization, and OS-independent APIs for the Swift l… | 88 | 5439 | active |
| hustcc/timeago.js timeago.js is a tiny (<2kb) zero-dependency JavaScript/TypeScript library that formats dates as relative 'time ago' / 'time in' strings (e.… | 67 | 5367 | stable |
| wanasit/chrono Chrono is a natural language date parser library for JavaScript/TypeScript that extracts dates and times from arbitrary text. It handles re… | 95 | 5291 | active |
| dromara/carbon Carbon is a lightweight, semantic, and developer-friendly time and date library for Go with zero third-party dependencies and 100% unit tes… | 100 | 5220 | active |
| jinzhu/now Now is a Go library providing a time toolkit for computing time boundaries (beginning/end of minute, day, week, month, quarter, year) and p… | 58 | 4705 | stable |
| spulec/freezegun FreezeGun is a Python library that lets tests 'travel through time' by mocking datetime and time module functions. It provides a decorator … | 47 | 4527 | stable |
| nathanreyes/v-calendar VCalendar is an elegant calendar and date picker plugin for Vue.js 3, providing VCalendar and VDatePicker components with attributes, popov… | 23 | 4518 | stable |
| spencermountain/spacetime Spacetime is a lightweight, zero-dependency JavaScript library for calculating dates and times across timezones. It provides a Moment-like … | 93 | 4108 | stable |
| sfsam/Itsycal Itsycal is a tiny open-source calendar that lives in the macOS menu bar, showing dates and upcoming events as a companion to the Mac Calend… | 77 | 4020 | active |
| chronotope/chrono Chrono is a date and time library for Rust providing timezone-aware DateTime types, timezone-naive variants, and strftime-style parsing and… | 86 | 3921 | stable |
| ankane/groupdate A Ruby gem that makes it simple to group ActiveRecord data by time periods like day, week, month, or hour, with full time zone and daylight… | 72 | 3886 | stable |
| jkbrzt/rrule rrule.js is a JavaScript/TypeScript library for creating, parsing, and querying recurrence rules for calendar dates as defined in the iCale… | 23 | 3744 | stable |
| tc39/proposal-temporal The TC39 Temporal proposal, a Stage 4 ECMAScript standard adding a modern date and time API to JavaScript as a global namespace object with… | 62 | 3706 | stable |
| unicode-org/icu ICU (International Components for Unicode) is the Unicode Consortium's mature C/C++ and Java library providing Unicode and globalization su… | 79 | 3611 | stable |
| HowardHinnant/date A C++11/14/17 date and time library built on <chrono>, providing field types like year_month_day, timezone support via a complete IANA tz d… | 84 | 3436 | stable |
| travisjeffery/timecop Timecop is a Ruby gem that provides time travel, time freezing, and time acceleration capabilities for testing time-dependent code. It offe… | 75 | 3426 | stable |
| wolfcw/libfaketime libfaketime is an LD_PRELOAD library that intercepts system calls retrieving the current date and time, reporting faked times to a single a… | 85 | 3122 | active |
| uxsolutions/bootstrap-datepicker A jQuery-based datepicker widget for Twitter Bootstrap applications. It provides a calendar popup for selecting dates in forms, with locali… | 38 | 12641 | maintenance |
| nodatime/nodatime Noda Time is an alternative date and time library for .NET, offering a clearer and more precise API than the built-in DateTime types. It pr… | 72 | 3003 | stable |
| BurntSushi/jiff Jiff is a high-level datetime library for Rust offering date, time, timestamp, and timezone-aware primitives with DST-safe arithmetic, roun… | 61 | 2951 | stable |
| GitHub Elements GitHub Elements is a collection of web components from GitHub, including the <relative-time> custom element that extends the standard <time… | 75 | 2903 | active |
| t1m0n/air-datepicker Air Datepicker is a lightweight, dependency-free JavaScript datepicker and calendar component written in pure ES6 with native CSS variables… | 29 | 2873 | active |
| scrapinghub/dateparser A Python library that parses human-readable dates in almost any format, including relative expressions like 'two weeks ago', timestamps, an… | 92 | 2861 | stable |
| Kotlin/kotlinx-datetime A Kotlin multiplatform library for working with dates, times, and time zones based on the ISO 8601 standard. It provides a minimal, pragmat… | 83 | 2823 | active |
| mattlewis92/angular-calendar A flexible calendar component library for Angular 20.2+ that displays events in month, week, and day views. It is the successor of angular-… | 63 | 2817 | active |
| dangrossman/daterangepicker A JavaScript date range, date, and time picker component that attaches to any webpage element and shows a dropdown with two calendars. It s… | 23 | 10973 | maintenance |
| CalendarKit CalendarKit is a Swift calendar UI library for iOS and Mac Catalyst that resembles the Apple Calendar app out of the box while remaining cu… | 65 | 2702 | active |
| dateutil/dateutil python-dateutil is a Python library providing powerful extensions to the standard datetime module. It offers flexible date parsing, relativ… | 66 | 2638 | stable |
| agiapp/BRPickerView BRPickerView is an Objective-C library of picker components for iOS, including a date picker with 15+ date styles, a text picker supporting… | 66 | 2634 | active |
| Croner Croner is a zero-dependency JavaScript/TypeScript library for triggering functions on cron schedules and evaluating cron expressions. It su… | 86 | 2609 | stable |
| formkit/tempo Tempo is a tiny, tree-shakable JavaScript/TypeScript library for parsing, formatting, manipulating, and internationalizing dates and times.… | 72 | 2586 | active |
| henninghall/react-native-date-picker A React Native date and time picker component with native implementations for Android and iOS. It supports date, time, and datetime modes, … | 37 | 2508 | active |
| ice-cube-ruby/ice_cube ice_cube is a Ruby library for defining and querying recurring event schedules using an iCalendar-inspired rule syntax. It lets you build r… | 48 | 2469 | stable |
| ariebovenberg/whenever Whenever is a Python library providing type-safe datetime and timezone handling that prevents naive/aware mixing at the type level and corr… | 94 | 2406 | active |
| davedelong/time A Swift package providing robust, type-safe date and time calculations built around regional clocks and calendar-aware value types. It prev… | 83 | 2341 | active |
| namespace-ee/react-calendar-timeline A modern and responsive React timeline component for visualizing time-based events and groups. It is written in TypeScript and supports Rea… | 89 | 2157 | active |
| itchyny/calendar.vim A calendar application implemented as a Vim plugin, providing calendar, clock, and year views inside the editor. It can sync with Google Ca… | 69 | 2035 | active |
| basecamp/local_time A Rails engine with a companion JavaScript component that renders <time> elements in UTC server-side and converts them to the browser's loc… | 77 | 2002 | stable |
| patchthecode/JTAppleCalendar JTAppleCalendar is an unofficial, fully customizable calendar view library for iOS written in Swift. It supports month and week views, rang… | 32 | 7650 | maintenance |
| vercel/little-date little-date is a small TypeScript library for formatting date ranges into short, readable strings like 'Jan 1 - 12' or 'Q1 2023'. It is bui… | 42 | 1966 | active |
| vacanza/holidays A fast, efficient Python library for generating country- and subdivision-specific sets of government-designated holidays on the fly. It mak… | 100 | 1961 | active |
| aleksanderwozniak/table_calendar TableCalendar is a highly customizable, feature-packed calendar widget for Flutter apps. It supports month, two-week, and week formats with… | 76 | 1960 | active |
| MatthewYork/DateTools DateTools is an Objective-C and Swift library that simplifies date and time handling in iOS, inspired by .NET's DateTime and Time Period Li… | 23 | 7173 | maintenance |
| unicode-org/icu4x ICU4X is a Rust implementation of Internationalization Components of Unicode (ICU) built on CLDR data, designed to be small, modular, and f… | 91 | 1866 | active |
| LiveSplit LiveSplit is a sleek, highly customizable timer application for speedrunners with features like auto splitting, game time detection, and sp… | 87 | 1857 | active |
| myusuf3/delorean Delorean is a Python library that simplifies working with datetimes, offering a cleaner API for shifting, manipulating, and generating date… | 79 | 1823 | active |
| vicolo-dev/chrono Chrono is a modern, open-source clock application for Android offering alarms, timers, stopwatch, and world clock features. It is built wit… | 22 | 1791 | active |
| Vuepic Datepicker A feature-rich datepicker component library for Vue 3, supporting single dates, ranges, time, month, year, quarter, and week pickers with m… | 85 | 1767 | active |
| yannecer/NCalendar An Android calendar UI library written in Kotlin that mimics MIUI, DingTalk, and Huawei calendar styles. It supports month and week views w… | 23 | 1726 | stable |
| spatie/opening-hours A PHP library for modeling, querying, and formatting a business's opening hours, including regular weekly schedules and date-based exceptio… | 98 | 1720 | stable |
| spatie/period A PHP library for comparing multiple date periods, computing overlaps, differences, and basic comparisons between any number of ranges. Per… | 62 | 1702 | active |
| 6tail/lunar-javascript A dependency-free JavaScript library for converting and querying Solar (Gregorian), Chinese Lunar, Buddhist, and Taoist calendars. It provi… | 56 | 1694 | stable |
| excid3/simple_calendar A Ruby gem for Ruby on Rails that renders calendars of any size (day, week, month, or custom ranges) with simple view helpers. It is ORM-ag… | 88 | 1667 | stable |
| js-joda/js-joda js-joda is an immutable date and time library for JavaScript, ported from the Java threeten-backport (JSR-310 / java.time). It provides a d… | 67 | 1662 | stable |
| WickyNilliams/cally Cally is a set of small, feature-rich calendar web components built in TypeScript, providing building blocks for date selection (single, mu… | 70 | 1657 | active |
| adzap/validates_timeliness A Ruby gem providing complete date, time, and datetime validation for Rails and ActiveModel, supporting multiple ORMs and custom date/time … | 76 | 1615 | active |
| prolificinteractive/material-calendarview A Material design back port of Android's CalendarView, provided as a customizable calendar UI widget for Android apps. It supports single/m… | 23 | 5897 | maintenance |
| simshaun/recurr Recurr is a PHP library for parsing, building, and transforming recurrence rules (RRULE from RFC 5545) into DateTime objects. It is designe… | 49 | 1601 | active |
| MarceloPrado/flash-calendar Flash Calendar is a fast, lightweight React Native calendar library built on Flash List, supporting date ranges, infinite scroll, localizat… | 61 | 1507 | active |
| harrisiirak/cron-parser A TypeScript/JavaScript library for parsing and manipulating cron expressions. It supports timezone handling, DST transitions, predefined e… | 99 | 1501 | active |
| LunarBar-app/LunarBar LunarBar is a free, open-source macOS menu bar app that displays a compact calendar with Chinese lunar calendar dates, public holidays, and… | 92 | 1501 | active |
| melvitax/DateHelper DateHelper is a Swift Date extension library for creating, comparing, modifying, and formatting dates. It supports parsing strings with pre… | 23 | 1494 | stable |
| ludoguenet/laravel-zap Laravel Zap is a calendar and scheduling package for Laravel that lets any Eloquent model manage availabilities, appointments, blocked time… | 85 | 1471 | active |
| python-babel/babel Babel is the standard Python library for internationalization and localization, built on CLDR data. It provides locale-aware date, number, … | 73 | 1467 | stable |
| olebedev/when when is a Go library that parses natural language date and time expressions like 'tonight at 11:10 pm' or 'next tuesday 14:00' into concret… | 62 | 1460 | active |
| nager/Nager.Date Nager.Date is a .NET-based public holiday data project covering 200+ countries, exposed via a free public REST API, a hosted website, a Doc… | 92 | 1417 | active |
| JodaOrg/joda-time Joda-Time is a quality date and time library for Java, serving as the de facto standard replacement for the poor JDK date/time classes prio… | 94 | 4982 | maintenance |
| liriansu-opus/chinese-calendar A Python library that determines whether a given date is a Chinese statutory holiday or workday, based on the State Council's official holi… | 61 | 1383 | active |
| cakephp/chronos CakePHP Chronos is a standalone PHP DateTime library providing immutable datetime, date-only, and time-only objects, originally based on Ca… | 95 | 1362 | active |
| liamcain/obsidian-periodic-notes An Obsidian plugin that extends daily notes with weekly and monthly notes, providing commands to open, create, and navigate periodic notes.… | 23 | 1362 | stable |
| time-rs/time A Rust library for date and time handling, fully interoperable with the standard library and mostly compatible with no_std environments. It… | 94 | 1338 | stable |
| dbreunig/whenwords whenwords is a relative time formatting library that ships only a specification (SPEC.md), language-agnostic test cases (tests.yaml), and i… | 41 | 1337 | active |
| bokmann/business_time A Ruby gem that extends ActiveSupport's time math helpers to account for business hours, business days, weekends, and holidays. It lets dev… | 54 | 1330 | stable |
| Rewrite Framework PrettyTime is an open-source Java library for formatting dates and times as human-readable, relative timestamps in a social media style (e.… | 48 | 1324 | stable |
| vsme/chinese-days A TypeScript/npm library for querying Chinese statutory holidays, adjusted workdays (调休), regular workdays, and the 24 solar terms, plus lu… | 78 | 1307 | active |
| wdullaer/MaterialDateTimePicker An Android library providing Material Design styled date and time picker dialogs with a themable API. It is based on the Android framework'… | 23 | 4624 | maintenance |
| uvarov-frontend/vanilla-calendar-pro Vanilla Calendar Pro is a lightweight, dependency-free JavaScript date and time picker component written in TypeScript that works with any … | 97 | 1286 | active |
| andrewplummer/Sugar Sugar is a JavaScript utility library for working with native objects like Array, Date, Number, and String, offering expressive methods for… | 23 | 4504 | maintenance |
| square/android-times-square TimesSquare is a standalone Android widget library providing a calendar view for picking single dates, date ranges, or multiple dates. It i… | 10 | 4404 | maintenance |
| sindresorhus/pretty-ms A small JavaScript library that converts milliseconds into human-readable duration strings like '15d 11h 23m 20s'. It supports options for … | 84 | 1216 | stable |
| jmrozanec/cron-utils cron-utils is a Java library for defining, parsing, validating, and migrating cron expressions across different cron dialects (Unix, Quartz… | 44 | 1210 | active |
| icalendar/icalendar A Ruby library for parsing, creating, and manipulating iCalendar (.ics) files as defined by RFC-5545. It supports building calendars and ev… | 77 | 1205 | active |
| HangfireIO/Cronos Cronos is a .NET library for parsing Cron expressions and calculating their next occurrences. It handles time zones and daylight saving tim… | 84 | 1190 | stable |
| collective/icalendar A Python library for parsing and generating iCalendar (RFC 5545) files. It can create, inspect, and modify calendar events, todos, journals… | 96 | 1181 | stable |
| marnusw/date-fns-tz A complementary library for date-fns v3 that adds IANA time zone support using the browser's Intl API, so no time zone data needs to be bun… | 23 | 1180 | stable |
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