Markwhen document guide
Meridiem stores plain-text documents. Use .mw for Markwhen timelines and schedules; use .md for Markdown notes, prose, and documentation. Markwhen is a Markdown-like timeline language, not a Markdown table of dates.
When calling document tools, pass raw source text, without an enclosing Markdown code fence. Preserve the existing document format when editing.
Basic Markwhen syntax
An event begins with a date or date range, a colon, and its description. Additional description lines follow the event. Prefer ISO dates (YYYY-MM-DD) to avoid ambiguous numeric dates.
---
title: Project plan
timezone: America/New_York
---
# Planning
2026-10-14: Project kickoff #milestone
Discuss goals and responsibilities.
2026-10-15 / 2026-10-16: Design review
- [ ] Review proposals
- [ ] Record decisions
## Implementation
2026-10-19: Begin implementation
The optional YAML header contains metadata such as title and timezone. Delimit it with ---. Sections use Markdown headings (# through ######); a heading of the same or higher level closes the previous section. Tags such as #milestone label events. Event descriptions can contain Markdown, including checklists and links.
Markdown documents
For .md, write ordinary Markdown headings, paragraphs, lists, and links. Use .mw when the user wants events rendered as a timeline or schedule.
More documentation
Consult the detailed syntax documentation before using advanced features such as recurrence, relative dates, custom date formats, or tag configuration.