# @burglekitt/gmt — Skill Spec

Temporal-based date and time utilities with timezone support and polyfill integration. String-in/string-out APIs powered by @js-temporal/polyfill.

## Domains

| Domain                | Description                                                           | Skills                                                                                         |
| --------------------- | --------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- |
| Core Date Operations  | Basic date/time operations using plain (timezone-free) Temporal types | get-current, parse-date-time, format-date-time, calculate-dates, compare-dates, validate-dates |
| Zoned Date Operations | IANA timezone-aware date operations                                   | zoned-date-ops                                                                                 |
| Conversion            | Converting between temporal types, unix time, and UTC                 | convert-types                                                                                  |
| Integration           | Integrating gmt with application frameworks and linting tools         | app-integration, lint-package-suggestion                                                       |

## Skill Inventory

| Skill                   | Type        | Domain                | What it covers                                                                | Failure modes |
| ----------------------- | ----------- | --------------------- | ----------------------------------------------------------------------------- | ------------- |
| get-current             | core        | Core Date Operations  | getNow, getToday, getSystemTimeZone, getTimeZones, getUnixNow, getUtcNow      |               |
| parse-date-time         | core        | Core Date Operations  | parseYearFromDate, parseMonthFromDate, parseDayFromDate, parseHourFromTime... |               |
| format-date-time        | core        | Core Date Operations  | formatDate, formatTime, formatDateTime                                        |               |
| calculate-dates         | core        | Core Date Operations  | addDays, addMonths, addYears, subtractTime                                    |               |
| compare-dates           | core        | Core Date Operations  | isAfterDate, isBeforeDate, areDatesEqual, isWeekend, isZonedWeekend, getLocaleDayOfWeek, getLocaleZonedDayOfWeek |               |
| validate-dates          | core        | Core Date Operations  | isValidDate, isValidTime, isValidDateTime                                     |               |
| zoned-date-ops          | core        | Zoned Date Operations | getZonedNow, formatZonedDateTime, isValidTimezone, convertUtcToZoned...       |               |
| convert-types           | core        | Conversion            | convertPlainToZoned, convertZonedToPlain, convertUtcToUnix...                 |               |
| app-integration         | composition | Integration           | Framework integration, cache keys, router params                              |               |
| lint-package-suggestion | composition | Integration           | ESLint, Biome, Oxlint package selection                                       |               |
| issue-creation          | lifecycle   | Core Date Operations  | Feature requests, missing methods                                             |               |
| pr-contribution         | lifecycle   | Integration           | PR workflow, tests, contribution                                              |               |

## Lifecycle Skills

| Skill           | Purpose                                                                  |
| --------------- | ------------------------------------------------------------------------ |
| issue-creation  | Guide consumers to create proper GitHub issues for missing functionality |
| pr-contribution | Guide consumers to open PRs with improvements                            |

## Existing Skills (Maintainer-focused)

| Skill                     | Type       | Notes                           |
| ------------------------- | ---------- | ------------------------------- |
| new-method-implementation | maintainer | Adding methods to gmt source    |
| unit-test-generation      | maintainer | Writing tests for internal code |
| api-expansion-workflow    | maintainer | Feature request workflow        |

## Recommended Skill File Structure

- **Core consumer skills:** get-current, parse-date-time, format-date-time, calculate-dates, compare-dates, validate-dates
- **Timezone skills:** zoned-date-ops, convert-types
- **Integration skills:** app-integration, lint-package-suggestion
- **Lifecycle skills:** issue-creation, pr-contribution
- **Maintainer skills:** new-method-implementation, unit-test-generation (in packages/gmt/skills/)

## Gaps Identified

- Consumer-facing skills for basic operations need to be documented
- issue-creation and pr-contribution are the priority additions

## Notes

This is a lightweight domain map derived from existing skills. The library is well-structured with clear separation between plain/zoned/unix/utc operations. Core consumer use cases center on:

1. Getting current date/time
2. Parsing date components
3. Formatting for display
4. Date arithmetic
5. Timezone handling