---
id: "date_jp_era"
kind: "pattern"
status: "draft"
is_pii: false
categories: ["datetime"]
country: ["JP"]
langs: ["ja"]
quality: 80
url: "https://registry.apicrafter.io/datatype/date_jp_era"
---

# Date in a Japanese era (wareki) (`date_jp_era`)

> **Draft.** Draft records have not been reviewed yet and may be incomplete or wrong; do not treat them as authoritative for legal or compliance decisions.

Calendar date written with a Japanese era name (gengō) and the year of that era, for example 令和7年7月20日 or the abbreviated form 平成 9. 4.27. 元 stands for the first year of an era. The eras of modern dates are 明治 (from 1868), 大正 (1912), 昭和 (1926), 平成 (1989) and 令和 (2019); the Gregorian year is the start year of the era plus the era year minus one.

- Pattern of: `date`
- Personal data (PII): no
- Categories: Date and time (datetime)
- Countries: Japan (JP)
- Languages: Japanese (ja)

## Detection

Regular expression (Python `re`):

```
^(?:明治|大正|昭和|平成|令和)\s*(?:元|[0-9０-９]{1,2})[年.．]\s*[0-9０-９]{1,2}[月.．]\s*[0-9０-９]{1,2}日?$
```

## Examples

- `平成 9. 4.27` — 27 April 1997, as in a municipal election table
- `令和7.7.20` — 20 July 2025
- `令和元年5月1日` — 1 May 2019, the first day of Reiwa
- `2019年5月1日` (invalid example) — Gregorian year

## Translations

- ja: 和暦の日付

## Sources

- wikipedia: <https://en.wikipedia.org/wiki/Japanese_era_name>

## Quality

Score 80/100. Missing: mapping (Wikidata, Schema.org, ...), detector coverage.

JSON: <https://registry.apicrafter.io/api/v1/datatypes/date_jp_era.json> · Edit: <https://github.com/apicrafter/metacrafter-registry/edit/main/data/datatypes/JP/datetime/date_jp_era.yaml>