XSD datatype

xs:gYear and friends

Gregorian fragments — a year, a month, a day, or a pair of them — for the dates that are genuinely partial.

The g-types cover recurring or partial dates: gYear (2026), gYearMonth (2026-08), gMonth (--08), gDay (---18) and gMonthDay (--08-18). The leading hyphens are part of the lexical form and are what people forget.

gMonth and gMonthDay are for recurring dates — a birthday, a fiscal month — where the year is deliberately absent rather than unknown.

Lexical space: YYYY for gYear; YYYY-MM for gYearMonth; --MM, ---DD, --MM-DD for the rest.
Derives from: Primitive type
Category: Date and time types
Facets: minInclusive, maxInclusive, minExclusive, maxExclusive, pattern, enumeration, whiteSpace

What validates

Every literal below is put through the schema validator on each test run, against the schema at the foot of this page.

2026
-0044
2026

What does not

26
The year is four digits minimum.
2026-08
That is a gYearMonth, not a gYear.

What catches people out

gMonth is '--08' with two leading hyphens, and gDay is '---18' with three. Omitting them is the usual failure.
Years before 1 CE are negative and there is no year zero: -0001 is 1 BCE.
All of them accept an optional timezone, same as xs:date.

The schema used

This is the exact schema the literals above are validated against. Paste it into the validator with one of them to see the result yourself.

schema.xsd

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="v" type="xs:gYear"/>
</xs:schema>

Open the XSD validator

All 29 datatypes and facets

Get started

Bring order to the XML your team can't afford to ignore.

Create a free account and get a private workspace to search, validate, diff, and monitor your XML feeds, sitemaps, schemas, and vendor integrations.

Get started free Sign in