# ThisMonth

Resolve "thisMonth" to a concrete ISO date range relative to your run time, this month...

- Repository: https://github.com/HarnessMD/munder-difflin (9274 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add HarnessMD/munder-difflin --skill thisMonth -g -a claude-code -y`
Codex: `npx skills add HarnessMD/munder-difflin --skill thisMonth -g -a codex -y`
Cursor: `npx skills add HarnessMD/munder-difflin --skill thisMonth -g -a cursor -y`
Gemini CLI: `npx skills add HarnessMD/munder-difflin --skill thisMonth -g -a gemini-cli -y`

## Description

Resolve "thisMonth" to a concrete ISO date range relative to your run time, this month so far (1st → today). Returns inclusive civil dates plus exact UTC instants so you have temporal context without computing dates by hand. Read-only: no writes, no network. Use before a month-to-date task (MTD metrics, "so far this month").

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

## /thisMonth

Get the concrete date range for **this month so far (1st → today)** by running the bundled resolver:

```bash
node "$AGENT_DIR/.claude/skills/temporal/when.mjs" thisMonth
```

It prints a human-readable line plus a JSON record:

- `start` / `end`, inclusive civil dates (`YYYY-MM-DD`) in your local timezone
- `startUtc` / `endExclusiveUtc`, the same window as a half-open `[start, end)`
  range of exact UTC instants, for timestamp-based queries
- `days`, `timezone`, `asOf`, the span, your timezone, and when this resolved

Use the returned dates as the time bounds for the task at hand. **Do not derive
dates by hand**, this resolver is the source of truth. For the full window list
or an arbitrary range (e.g. `last45days`, `last6months`), see the `/temporal` skill.