Condates — Conditional Dates for DatoCMS

A DatoCMS plugin for entering historical or partial dates where some components (year, month, day) may be unknown.

Standard date fields require a complete date. When documenting historical events, artworks, archaeological finds, or any record with uncertain dating, editors often know only the year, or the year and month. Condates solves this by providing a conditional date editor that adapts to what the editor actually knows.

Features

• Partial dates — enter just a year, year + month, or a full date
• Cascading controls — month unlocks only after year is set; day unlocks only after month is set
• Era support — CE (Common Era) or BCE (Before Common Era)
• Circa flag — mark a date as approximate
• Leap-year validation — day options adjust to the correct number of days for the selected month and year
• Workflow-aware — all controls respect DatoCMS field locking (ctx.disabled)

Setup

1. Install the plugin on your DatoCMS project
2. Create a JSON field on your model
3. In the field's Presentation tab, select Conditional Date as the field editor

Output

The field stores a JSON string with the following structure:

Full date

{"year": 1492, "month": 10, "day": 12, "era": "CE", "circa": false}

Year only (approximate)

{"year": 44, "month": null, "day": null, "era": "BCE", "circa": true}

Year and month

{"year": 2024, "month": 3, "day": null, "era": "CE", "circa": false}

Empty field

null

Field reference

Key	Type	Description
year	integer | null	Year value (minimum 1)
month	integer | null	Month (1-12), requires year
day	integer | null	Day (1-28/29/30/31), requires month
era	"CE" | "BCE" | null	Era indicator, requires year, defaults to CE
circa	boolean | null	Whether the date is approximate, requires year

All components except year are conditional — they are only set when their parent component is present. Clearing a parent cascades: clearing year resets everything to null; clearing month resets day to null.

The JSON value is queryable via GraphQL as a string. Date construction and formatting is left to the frontend consumer.

Development

npm run dev       # Start dev server
npm run build     # TypeScript check + production build
npm run preview   # Preview production build