# lastMonth

> Resolve "lastMonth" to a concrete ISO date range relative to your run time — the previous full calendar month. 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 task over last month (monthly reports, month-end summaries).

- Skill: `chaitanyagiri/lastmonth` (Agent Skill)
- Install (CLI): `npx skillmds@latest add chaitanyagiri/lastmonth`
- Raw SKILL.md: https://api.skillmd.com/api/skills/chaitanyagiri/lastmonth/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: chaitanyagiri (https://skillmd.com/u/chaitanyagiri)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/chaitanyagiri/lastmonth

---


## /lastMonth

Get the concrete date range for **the previous full calendar month** by running the bundled resolver:

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

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.