edtf-date.biblatex

@article{item3-3, date={1998/unknown}}
@article{item3-4, date={1999/open}}
@article{item3-10, date={2004-04-05T14:34:00}}
@article{item5-1, date={0000}}
@article{item5-2, date={-0876}}
@article{item5-3, date={-0877/-0866}}
@article{item5-5, date={-0343-02}}
@article{item5-8, date={1723~}}
@article{item5-9, date={1723?}}
@article{item5-10, date={1723?~}}
@article{item5-11, date={2004-22}}
@article{item5-12, date={2004-24}}
@article{item5-13, date={20uu}}
@article{item5-14, date={y-123456789}}

---
references:
- id: item3-3
  type: article-journal
  issued:
  - year: '1998'
  - {}

- id: item3-4
  type: article-journal
  issued:
  - year: '1999'
  - {}

- id: item3-10
  type: article-journal
  issued:
  - year: '2004'
    month: '4'
    day: '5'

- id: item5-1
  type: article-journal
  issued:
  - year: '-1'

- id: item5-2
  type: article-journal
  issued:
  - year: '-877'

- id: item5-3
  type: article-journal
  issued:
  - year: '-878'
  - year: '-867'

- id: item5-5
  type: article-journal
  issued:
  - year: '-344'
    month: '2'

- id: item5-8
  type: article-journal
  issued:
  - year: '1723'
    circa: '1'

- id: item5-9
  type: article-journal
  issued:
  - year: '1723'

- id: item5-10
  type: article-journal
  issued:
  - year: '1723'
    circa: '1'

- id: item5-11
  type: article-journal
  issued:
  - year: '2004'
    season: '2'

- id: item5-12
  type: article-journal
  issued:
  - year: '2004'
    season: '4'

- id: item5-13
  type: article-journal
  issued:
  - year: '2000'
  - year: '2099'

- id: item5-14
  type: article-journal
  issued:
  - year: '-123456790'
...