Introduction

Markwhen is a markdown-like journal language. You write markdown-ish text and it gets converted into JSON which can then be rendered into a timeline or other view.

Use the editor at meridiem.markwhen.com or read more about the syntax.

Markwhen input

Output

{ "events": { "properties": [], "tags": [], "title": "", "children": [ { "firstLine": { "full": "2025-04-09: Single date", "datePart": "2025-04-09", "rest": " Single date", "restTrimmed": "Single date" }, "properties": [], "textRanges": { "whole": { "from": 0, "to": 24, "type": "event" }, "datePart": { "type": "dateRange", "from": 0, "to": 10 }, "definition": { "type": "dateRange", "from": 0, "to": 10 } }, "dateRangeIso": { "fromDateTimeIso": "2025-04-09T00:00:00.000+00:00", "toDateTimeIso": "2025-04-10T00:00:00.000Z" }, "tags": [], "supplemental": [], "matchedListItems": [], "isRelative": false }, { "firstLine": { "full": "2025-01-22 / 2026-10-24: Date range", "datePart": "2025-01-22 / 2026-10-24", "rest": " Date range", "restTrimmed": "Date range" }, "properties": [], "textRanges": { "whole": { "from": 24, "to": 61, "type": "event" }, "datePart": { "type": "dateRange", "from": 24, "to": 47 }, "definition": { "type": "dateRange", "from": 24, "to": 47 } }, "dateRangeIso": { "fromDateTimeIso": "2025-01-22T00:00:00.000+00:00", "toDateTimeIso": "2026-10-25T00:00:00.000Z" }, "tags": [], "supplemental": [], "matchedListItems": [], "isRelative": false }, { "firstLine": { "full": "Dec 1 2025: Supports multiple date formats", "datePart": "Dec 1 2025", "rest": " Supports multiple date formats", "restTrimmed": "Supports multiple date formats" }, "properties": [], "textRanges": { "whole": { "from": 61, "to": 128, "type": "event" }, "datePart": { "type": "dateRange", "from": 61, "to": 71 }, "definition": { "type": "dateRange", "from": 61, "to": 71 } }, "dateRangeIso": { "fromDateTimeIso": "2025-12-01T00:00:00.000Z", "toDateTimeIso": "2025-12-02T00:00:00.000Z" }, "tags": [], "supplemental": [ { "raw": "And longer descriptions", "type": "text" } ], "matchedListItems": [], "isRelative": false } ] }, "ids": {}, "ranges": [ { "type": "dateRange", "from": 0, "to": 10 }, { "type": "dateRangeColon", "from": 10, "to": 11 }, { "type": "dateRange", "from": 24, "to": 47 }, { "type": "dateRangeColon", "from": 47, "to": 48 }, { "type": "dateRange", "from": 61, "to": 71 }, { "type": "dateRangeColon", "from": 71, "to": 72 } ], "foldables": { "24": { "startIndex": 59, "endIndex": 60, "type": "event", "foldStartIndex": 59, "startLine": 1 }, "61": { "startIndex": 103, "endIndex": 127, "type": "event", "foldStartIndex": 103, "startLine": 3 } }, "header": { "dateFormat": "M/d/y" }, "parseMessages": [], "documentMessages": [ { "type": "warning", "message": "Timezone not specified. Specifying a `timezone` in the header is highly recommended." } ], "parser": { "version": "0.14.12" } }

View example timeline that uses all of markwhen's features.

Read more about markwhen's syntax, the parser, or views.

Diagram of repositories