AGENTS.md
Guidance for coding agents working on AlexandrAI Tools Business Days in the alexandrai-tools project.
Project overview
This guide covers src/tools/business-days/index.ts. The tool converts dates to UTC epoch days, sorts endpoints, reports inclusive total calendar days, chooses an inclusive or exclusive counting window, and counts Monday through Friday using full-week arithmetic plus a partial-week remainder.
Primary source files
- src/tools/business-days/index.ts defines meta, BusinessDaysResult, isoToEpochDay, epochDayToWeekday, and countBusinessDays.
- src/tools/business-days/index.test.ts covers inclusive weekday spans, weekends, same-day weekdays, two full weeks, order independence, month crossing, exclusive endpoints, adjacent dates, and invalid dates.
- src/tools/business-days/Body.astro owns browser controls.
- src/tools/business-days/i18n.ts owns localized copy.
- src/lib/tools.ts registers metadata.
Setup commands
npm install npm test npm run typecheck npm run build npm run dev
Change rules
- Use UTC epoch days for date math.
- Sort input dates internally so order does not matter.
- Report totalDays as inclusive calendar days from start to end.
- When inclusive is true, count both endpoints if they are weekdays.
- When inclusive is false, exclude both endpoints.
- Count only Monday through Friday as business days.
- If holidays are added, keep them as an explicit option and do not alter base weekday behavior.
Testing
Test Monday-Friday, Monday-Sunday, weekend-only spans, same-day weekday, same-day weekend, two full weeks, reversed inputs, exclusive endpoint spans, adjacent dates, month crossings, invalid format, and future holiday exclusion.
PR checklist
- npm test passes for business-days.
- Timezone, UTC, and rounding behavior remain documented.
- Invalid-input behavior is covered by tests.
- UI labels, metadata, and pure date or time logic stay in sync.