Zero-dependency JavaScript API for managing fuzzy dates.
This package implements EDTF (levels 0, 1 and 2), which extended over the ISO-8601 standard to add fuzziness, and was eventually integrated in ISO 8601-2019.
By fuzziness, we mean:
- uncertainty (
?), like "maybe June 2025" - (im)precision (
X), to express that some date has missing component(s) info - approximation (
~), like "around June 2025" - both (
%), like "maybe around June 2025"
| EDTF | ISO Standard | Contents |
|---|---|---|
| Level 0 (2012) | ISO-8601-1 (Basic rules) | Dates, intervals, but no fuzziness |
| Level 1 (2016) | ISO-8601-2 (Extensions) | Date part fuzziness, open intervals, seasons, big years |
| Level 2 (2019) | ISO-8601-2 (Extensions) | Per-component date fuzziness, digits uncertainty, extended seasons w/ quarters, dates sets, exponential years |
| Level 3 | ISO-8601-3 | Seasons intervals |
Accordingly, this API is split in level-specific sub-packages.
You can use Level0Date only for instance, but using Level2Date will implicitly rely on Level1Date which implicitly rely on Level0Date,
as each of those standards are extending one on another.
This package supports fuzziness/no fuzziness for:
- Dates
- Date components (year, month, day, hour, minute, second, timeshift), each of these referencing a Unit
- Intervals between two dates
- Durations
Each data type can be:
- instantiated programmatically (like
new EdtfDate({year: 2024, month: 8, day: 25, uncertain: true})); - parsed from EDTF strings by default (like
EdtfDate.fromString("2024-08-25~")), but you can use your own parser; - rendered in EDTF format by default (like
edtfDate.toString()), but you can use your own renderer, to render in some language words for instance.
The examples below apply for both JavaScript and TypeScript.
Dates, date components (year, month, etc.), intervals or durations can be instantiated fromString.
Dates, date components (year, month, etc.), intervals or durations can be instantiated through their own constructors.
See details in the Wiki.