Open-source alternatives to DateTools

Tempo is a JavaScript date manipulation library that provides a suite of tools for parsing, formatting, and calculating dates and times. It serves as a date arithmetic engine, a locale-aware formatter, and a timezone offset manager for native JavaScript date objects. The library includes a dedicated ISO 8601 date parser for validating and converting standardized strings into date objects. It handles geographic normalization through IANA timezone offset management and utilizes the native Internationalization API for region-specific date formatting. The project covers a broad range of date and

Pendulum is a Python datetime library used for creating, manipulating, and formatting date and time objects with native timezone awareness. It extends the native Python datetime class to maintain compatibility while providing a specialized engine for date arithmetic and timezone management. The library features a dedicated ISO 8601 and RFC 3339 parser that converts standardized strings into date objects without requiring manual format strings. It also includes a relative time generator for producing natural language descriptions of time differences and a timezone management tool that automati

Day.js is a lightweight utility for parsing, validating, and manipulating date objects. It provides a fluent, chainable interface that allows for complex time calculations and transformations to be performed through a sequence of readable method calls. By utilizing an immutable wrapper pattern, the library ensures data integrity by creating new instances for every operation rather than modifying existing objects. The project is distinguished by a minimalist core abstraction that maintains a small footprint by offloading non-essential features to an optional, modular plugin system. This archit

date-fns is a JavaScript date utility library providing a collection of pure functions for manipulating, formatting, and calculating dates and times. It serves as an immutable date manipulation library and a tool for time zone management, ensuring that date transformations are performed without modifying the original date objects. The library functions as a date formatting tool that converts date objects into human-readable strings using custom patterns and international locales. It includes a specific toolset for adjusting and calculating date representations across different geographical re

Spacetime is a JavaScript timezone library and date manipulation framework designed for parsing, formatting, and managing dates across global timezones. It provides an internationalization tool for localizing date components and includes static type definitions for TypeScript environments to ensure type checking and autocompletion. The project features a plugin system for custom date logic, allowing the injection of specialized methods and behaviors into date objects. This extensibility enables the implementation of project-specific time requirements through prototype-based method extensions.

timeago.js is a JavaScript library that converts timestamps into human-readable relative time strings. It functions as an internationalized date library that transforms static date and time data into descriptive statements of elapsed time. The project provides a dynamic time updater that automatically refreshes relative time labels on a webpage at regular intervals. It supports multilingual date localization, allowing time-elapsed statements to be translated into various languages using built-in or custom locale settings.

Presto is a distributed SQL query engine designed for high-performance analytical processing across heterogeneous data sources. It functions as a data federation platform and massively parallel processing engine, allowing users to execute interactive queries against diverse storage systems without requiring data migration. By mapping remote metadata and structures to a unified relational namespace, it enables seamless cross-platform analysis through a standard SQL interface. The engine distinguishes itself through a pluggable connector architecture and a shared-nothing distributed processing

Arrow is a Python date and time library designed for parsing, formatting, and manipulating date and time objects. It provides a simplified interface for these operations compared to the Python standard library. The library includes tools for converting standardized date strings via an ISO 8601 parser and transforming timestamps into human-readable relative strings across different locales. It also features a utility for translating timestamps between global timezones using location data objects. Additional capabilities cover date string formatting, time object generation, and the calculation

This project is a proposal for a new immutable date and time API in JavaScript. It serves as a precision time-tracking library and a multi-calendar date engine designed to replace the legacy Date object. The system is distinguished by its support for multiple calendar systems beyond the ISO standard and its use of IANA-based time zone resolution. It provides a framework for managing daylight saving transitions and UTC offsets while maintaining nanosecond precision for global timestamps. The API covers broad functional areas including complex date and time arithmetic, locale-aware formatting,

Joda-Time is a Java date and time library and framework used for parsing, representing, and calculating temporal data. It provides a thread-safe temporal API that uses immutable objects to ensure concurrency safety and adheres to the ISO8601 standard. The project is distinguished by its pluggable calendar system, which supports diverse chronologies including Gregorian, Buddhist, Coptic, Ethiopic, and Islamic calendars. It also functions as a time zone management tool, utilizing an internal IANA-based zone database to translate instants and update daylight savings rules independently of the ho

Luxon is a JavaScript library for parsing, validating, manipulating, and formatting dates and times. It provides a suite of immutable objects for managing points in time, durations, and intervals, ensuring that all transformations return new instances to maintain predictable state. The library distinguishes itself by leveraging the native Internationalization API and environment-based time zone databases. This architecture allows for localized date formatting and global time zone conversions without requiring external data files or additional dependencies. It also supports non-Gregorian calen

Scriban is a .NET text templating engine and embedded scripting language used for dynamic text generation. It functions as an abstract syntax tree manipulation tool and a template parser, allowing for the conversion of scripts into visitable trees for analysis, modification, and rendering. The engine is specifically designed for Native AOT compatibility, utilizing a reflection-free API to execute templates in trimmed environments. It also provides a dedicated parser and conversion system for Liquid templates, enabling the migration and execution of Liquid scripts within .NET. The project cov

DataFrame is a C++ tabular data library and manipulation engine designed for managing heterogeneous data in contiguous memory. It functions as a statistical analysis framework and time series analysis toolkit, providing the means to store, index, and transform multidimensional datasets. The project distinguishes itself through a high-performance execution model that utilizes column-major storage, SIMD-aligned memory allocation, and a thread-pool for parallel computations. It employs a visitor-based algorithm dispatch system and policy-driven transformations to decouple data processing logic f

Carbon is a date and time manipulation library for PHP that extends the native DateTime class. It provides a set of tools for calculating, formatting, and comparing dates and times using a simplified, human-readable syntax. The library utilizes a fluent interface and static factory methods to allow for chained method calls and intuitive object instantiation. It supports both mutable and immutable state options to manage how date objects are modified and returned. The toolset covers temporal data management, including time zone handling and localization-based formatting to convert date compon

This project is a documentation and tooling resource designed to guide the migration from heavy date libraries to native JavaScript functions. It provides a date API migration guide, a utility reference for native replacements of common date tasks, and an ESLint plugin to identify outdated library usage. The tooling identifies redundant date library patterns via a linting plugin that suggests modern native alternatives. This process supports legacy code refactoring and frontend bundle optimization by replacing external dependencies with built-in language functions. The resource covers broade

This is a JavaScript time conversion library designed to format millisecond integers as human-readable durations and parse unit-based strings back into total milliseconds. It serves as a utility for managing the transition between machine-readable durations and text representations. The library provides bidirectional mapping, allowing for the conversion of raw numbers to strings and the parsing of strings containing units like days, hours, and minutes back into numeric millisecond counts. It supports both abbreviated and full written-out time formats.

Carbon is a Go library for semantic date and time calculations, formatting, and parsing. It provides a semantic interface to simplify temporal data handling and improve the readability of date and time manipulations. The library is distinguished by its support for multi-calendar date conversion, allowing transformations between Gregorian, Chinese Lunar, Persian, and Hebrew calendar systems. It also includes a localized temporal framework that uses ISO 639-1 codes to format dates and relative time differences across multiple language locales. Additional capabilities cover global time zone man

This project is an educational resource and a collection of instructional materials for performing data manipulation and statistical analysis using Python. It provides a comprehensive set of guides and code examples for using the Pandas, NumPy, and Matplotlib libraries to analyze structured data. The resource includes a dedicated guide for reshaping, cleaning, and aggregating tabular data and time series via Pandas, alongside a reference for high-performance vectorized operations and linear algebra using NumPy. It also features tutorials for creating publication-quality charts, distribution p

Now is a date and time manipulation library for Go designed to generate precise calendar boundaries and convert time strings into structured objects. It serves as a utility for calculating the start and end timestamps for days, weeks, months, and years. The project provides tools for calculating specific weekdays relative to a reference point and performing date arithmetic to determine time ranges. It includes a toolkit for parsing date and time strings using configurable layouts and formats. The library functions as a wrapper for the standard Go time package to provide an interface for comp

Pendulum is a Python date and time library that provides a simplified interface for date arithmetic, ISO parsing, localization, and timezone management. It serves as a replacement for the standard library datetime module, extending existing classes to maintain compatibility while offering a more intuitive management interface. The library distinguishes itself through a natural language date formatter that translates time differences into localized strings and a dedicated ISO 8601 date parser. It also includes tools for time-dependent logic testing, allowing the system clock to be mocked or fi

Pikaday is a lightweight JavaScript datepicker library and client-side date input manager. It provides a standalone calendar interface for selecting dates in web applications as a zero-dependency UI component that operates without external frameworks or libraries. The tool features a modular CSS architecture that separates structural logic from visual presentation, allowing for flexible customization of the calendar layout. It includes built-in support for calendar localization, enabling the update of month names and weekday labels to match specific languages or regions. The library manages

Ark is a headless UI component library that delivers accessible, cross-framework primitives with behavior governed by finite state machines. It provides unstyled components that encapsulate logic and accessibility — including full keyboard navigation, focus management, and WAI-ARIA support — while leaving visual styling entirely to the consumer. Components expose scoped data attributes for CSS targeting and use state machines to produce predictable, testable interactive behavior across every state transition. The library distinguishes itself through a state propagation model that distributes

This project is a high-performance tabular data processing framework for R, designed to handle massive datasets with memory efficiency and speed. It provides an enhanced data structure that utilizes reference semantics and in-place modification to perform complex transformations without the overhead of unnecessary object copying. The library distinguishes itself through its low-level architectural optimizations, including multi-threaded parallel processing, radix-based sorting, and memory-mapped file parsing. By offloading critical data manipulation and aggregation routines to compiled C code

This project is a reusable React datepicker component providing an accessible, localized interface for selecting dates and times within web applications. It functions as an input field that triggers a calendar popup for precise temporal data entry. The component is designed for flexibility, allowing for a customizable calendar layout and the integration of custom external elements to trigger the picker. It supports marking holidays with custom labels and styles and implements date selection restrictions through boundaries, exclusion lists, and filter functions. The system includes comprehens

Get a formatted timestamp. Used in gulp, assemble, generate, and many others.

Flatpickr is a lightweight, dependency-free JavaScript library designed to provide a modular date and time selection interface for web applications. It functions as a versatile web component that integrates into existing forms, offering a consistent user experience for picking single dates, ranges, or multiple values while maintaining a clear separation between human-readable display strings and machine-readable data. The library distinguishes itself through a robust configuration-driven architecture that allows for dynamic runtime updates and extensive customization of date formatting via a

This project is a comprehensive collection of modular, reactive functions designed to streamline the development of user interfaces. It serves as a toolkit for managing application state, wrapping native browser hardware and system features, and encapsulating common logic patterns into reusable units. By binding asynchronous data sources, browser events, and system properties to component state, it provides a unified framework for building interactive web and desktop applications. The library distinguishes itself through its focus on composition and lifecycle management, allowing developers t