feat: date picker core

.editorconfig

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+
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+indent_style = space
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ARCHITECTURE.md

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+## Overview
+
+`@tanstack/time` is a headless utility library designed to facilitate the creation of time and calendar components across various JavaScript frameworks, including TypeScript/JavaScript, React, Solid, Vue, Svelte, and Angular. This document provides an overview of the architecture and design principles of the library.
+
+
+## Design Principles
+
+### Headless utilities
+The library provides core functionalities without imposing any UI constraints, allowing developers to build custom UI components tailored to their specific needs.
+
+### Framework agnostic
+Core logic is implemented in a framework-agnostic manner, ensuring compatibility across multiple frameworks.
+
+### Modular and extensible
+The library is designed to be modular, enabling developers to use only the parts they need and extend functionalities when required.
+
+### Type safety
+Leveraging TypeScript to provide a strongly typed API, ensuring better developer experience and reducing runtime errors.
+
+### Standards-based
+The library uses standards-based core logic, aligning with modern web standards and best practices.
+Internationalization and localization
+TanStack Time is designed to handle various locales, calendars, and timezones, addressing the complexities of global date and time representation.
+Core Modules
+### Time utilities
+The library provides a set of utilities for working with time, including parsing, formatting, and manipulating time values.
+
+### Calendar utilities
+Calendar utilities enable developers to work with calendar-related functionalities, such as date range calculations, month view generation, and event scheduling.
+
+### Date manipulation
+Utilities for performing date math, comparisons, grouping, and range operations.
+Formatting
+Flexible date and time formatting options based on locale, calendar, and timezone.
+
+## Project Structure
+
+The project is structured as follows:
+```lua
+├── packages                # Contains individual packages for different frameworks
+│   ├── time                # Core logic shared across all packages
+│        ├── src            # Core logic implementation
+│        ├── test           # Unit tests
+│   ├── {framework}-time    # Adapters for specific frameworks (e.g., react-time, vue-time)
+├── examples                # Example applications demonstrating library usage
+├── docs                    # Documentation files
+├── scripts                 # Build and test scripts
+```
+
+The core logic is implemented in the `time` package, which contains the shared functionality across all framework-specific packages. Each framework-specific package (e.g., `react-time`, `vue-time`) contains the necessary adapters to integrate the core logic with the respective framework.
+
+
+## API Design
+
+The API of @tanstack/time is designed to be intuitive and flexible. It provides a set of core functions that can be easily composed to build complex time and calendar functionalities. The API is consistent across different frameworks, ensuring a seamless developer experience when switching between frameworks.
+
+### Key API features include:
+
+Parsing of RFC 3339 date time strings, epoch time, and Date objects
+Formatting based on Intl.DateTimeFormat standards
+Date math operations
+Comparison and sorting utilities
+Grouping and range operations
+Timezone and DST handling
+
+## Extensibility
+The library is designed to be extensible, allowing developers to add custom functionalities or modify existing ones to suit their requirements. Developers can extend the core logic by creating custom utilities or by composing existing utilities in new ways.
+
+### Temporal API Integration
+TanStack Time leverages the upcoming Temporal API, using a polyfill maintained by the TC39 champions until it's fully ratified and implemented by all major browsers. This ensures forward compatibility and access to advanced date and time manipulation features.
+
+### Internationalization
+The library is built with internationalization in mind, addressing the complexities of different calendar systems, date formats, and time representations across various cultures and regions.
+
+### Performance Considerations
+
+Memoization is used for formatters to improve performance when repeatedly formatting dates.
+The library provides options for working with "simple" date representations (strings or numbers) to facilitate easier memoization in application code.
+
+### Compatibility
+While focusing on modern standards, TanStack Time also provides compatibility options for working with legacy date formats and parsing methods, ensuring broad applicability across different project requirements.

CODE_OF_CONDUCT.md

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+---
+title: Code of Conduct
+id: code-of-conduct
+---
+
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, sex characteristics, gender identity and expression,
+level of experience, education, socio-economic status, nationality, personal
+appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+- Using welcoming and inclusive language
+- Being respectful of differing viewpoints and experiences
+- Gracefully accepting constructive criticism
+- Focusing on what is best for the community
+- Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+- The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+- Trolling, insulting/derogatory comments, and personal or political attacks
+- Public or private harassment
+- Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+- Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at TANNERLINSLEY@GMAIL.COM. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see
+https://www.contributor-covenant.org/faq

README.md

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-# time
+# TanStack Time
+
+![TanStack Time Header](media/repo-header.png)
 
 🤖⏰ Headless utilities for building time and calendar components in TS/JS, React, Solid, Vue, Svelte and Angular
+
+<a href="https://twitter.com/intent/tweet?button_hashtag=TanStack" target="\_parent">
+  <img alt="#TanStack" src="https://img.shields.io/twitter/url?color=%2308a0e9&label=%23TanStack&style=social&url=https%3A%2F%2Ftwitter.com%2Fintent%2Ftweet%3Fbutton_hashtag%3DTanStack">
+</a><a href="https://discord.com/invite/WrRKjPJ" target="\_parent">
+  <img alt="" src="https://img.shields.io/badge/Discord-TanStack-%235865F2" />
+</a><a href="https://npmjs.com/package/@tanstack/time" target="\_parent">
+  <img alt="" src="https://img.shields.io/npm/dm/@tanstack/time.svg" />
+</a><a href="https://bundlephobia.com/result?p=@tanstack/time" target="\_parent">
+  <img alt="" src="https://badgen.net/bundlephobia/minzip/@tanstack/time" />
+</a><a href="#badge">
+    <img alt="semantic-release" src="https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg">
+  </a><a href="https://github.com/tanstack/time/discussions">
+  <img alt="Join the discussion on Github" src="https://img.shields.io/badge/Github%20Discussions%20%26%20Support-Chat%20now!-blue" />
+</a><a href="https://bestofjs.org/projects/time"><img alt="Best of JS" src="https://img.shields.io/endpoint?url=https://bestofjs-serverless.now.sh/api/project-badge?fullName=tanstack%2Ftime%26since=daily" /></a><a href="https://github.com/tanstack/time" target="\_parent">
+  <img alt="" src="https://img.shields.io/github/stars/tanstack/time.svg?style=social&label=Star" />
+</a><a href="https://twitter.com/tan_stack" target="\_parent">
+  <img alt="" src="https://img.shields.io/twitter/follow/tan_stack.svg?style=social&label=Follow @TanStack" />
+</a><a href="https://twitter.com/tannerlinsley" target="\_parent">
+  <img alt="" src="https://img.shields.io/twitter/follow/tannerlinsley.svg?style=social&label=Follow @TannerLinsley" />
+</a>
+
+Enjoy this library? Try the entire [TanStack](https://tanstack.com)!
+
+## Visit [tanstack.com/time](https://tanstack.com/time) for docs, guides, API and more!

adr/choosing-a-date-time-handling-solution.md

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+# ADR: Choosing a Date and Time Handling Solution
+
+## Status
+
+Accepted, decided on Temporal API.
+
+## Context
+
+In modern web applications, accurate and efficient handling of dates and times is crucial. Traditional JavaScript `Date`` objects have several limitations and pitfalls, including:
+- Lack of support for different calendars
+- Difficulties with time zone conversions
+- Ambiguous and error-prone APIs for date and time manipulation
+
+These issues often lead to bugs and inefficiencies in handling date and time data, especially in complex applications that require extensive date and time manipulations, such as calendar applications.
+
+## Decision
+
+After evaluating several options, we have decided to adopt the Temporal API for all date and time handling in our application. Temporal is a new standard for working with dates and times in JavaScript, designed to provide a more reliable, readable, and easy-to-use API.
+
+### Evaluation of Alternatives
+
+1. **JavaScript `Date`**
+   - **Pros**:
+     - Built-in and requires no additional dependencies.
+     - Supported natively in all JavaScript environments.
+   - **Cons**:
+     - Ambiguous and error-prone API.
+     - Poor support for time zones and different calendars.
+     - Mutable objects, leading to potential bugs.
+     - Date arithmetic is complex and error-prone.
+
+2. **moment.js**
+   - **Pros**:
+     - Widely used and battle-tested.
+     - Rich feature set for date manipulation and formatting.
+   - **Cons**:
+     - Large library size, affecting bundle size.
+     - Mutable objects, leading to potential bugs.
+     - Moment.js is in maintenance mode, with no new features planned.
+
+3. **date-fns**
+   - **Pros**:
+     - Modular approach, allowing selective imports to reduce bundle size.
+     - Immutable and functional API.
+     - Good support for date arithmetic and formatting.
+   - **Cons**:
+     - Limited support for time zones without additional libraries.
+     - Requires combining multiple functions for complex operations.
+
+### Reasons for Choosing Temporal
+
+1. **Clarity and Readability**: Temporal's API is designed to be intuitive and readable. For example, creating a date in Temporal is straightforward and unambiguous:
+    ```javascript
+    const date = Temporal.PlainDate.from('2024-06-01');
+    ```
+    This is much clearer than the equivalent using `Date`:
+    ```javascript
+    const date = new Date('2024-06-01');
+    ```
+
+2. **Immutability**: Temporal objects are immutable, meaning that once created, they cannot be changed. This immutability prevents common bugs related to date manipulation and makes the code easier to reason about.
+
+3. **Comprehensive Support for Calendars and Time Zones**: Temporal natively supports different calendars and time zones, making it ideal for applications that need to handle internationalization and localization.
+
+4. **Precise Arithmetic Operations**: Temporal provides precise and easy-to-use methods for date and time arithmetic, avoiding the pitfalls of JavaScript `Date` arithmetic:
+    ```javascript
+    const nextMonth = date.add({ months: 1 });
+    ```
+
+5. **Better Error Handling**: Temporal's API is designed to throw errors for invalid operations, which helps in catching bugs early in the development process.
+
+6. **Standardization**: Temporal is an upcoming standard for date and time handling in JavaScript, which means it will have long-term support and improvements from the community and browser vendors.
+
+## Consequences
+
+### Positive
+
+- **Reduced Bugs**: By using Temporal, we expect to see a reduction in date and time-related bugs, especially those related to time zone conversions and date arithmetic.
+- **Improved Code Quality**: The clarity and immutability of Temporal will lead to more readable and maintainable code.
+- **Enhanced Features**: Support for multiple calendars and time zones will allow us to build more robust and feature-rich internationalized applications.
+
+### Negative
+
+- **Learning Curve**: Developers will need to learn the new Temporal API, which might slow down initial development.
+- **Polyfill Requirement**: Until Temporal is fully supported in all target environments, we will need to include a polyfill, which may slightly increase the bundle size.
+
+## Conclusion
+
+After evaluating various options for date and time handling in JavaScript, we have decided to adopt the Temporal API. Temporal provides a robust, readable, and reliable API that addresses the shortcomings of the existing `Date` object and offers comprehensive support for internationalization and time zone handling. Despite the initial learning curve and the need for a polyfill, the long-term benefits make Temporal the best choice for our application's needs.
+
+By documenting this decision, we ensure that future developers understand the rationale behind adopting Temporal and can build upon this foundation with confidence.