What causes "could not parse date string %s" in hibernate/hibernate-orm?

Rewrite literals and stored text to ISO format yyyy-MM-dd before Hibernate sees them

hibernate/hibernate-orm · error · HibernateException

could not parse date string %s

Error message

could not parse date string %s

What it means

JdbcDateJavaType.fromString() parses date text using DateTimeFormatter.ISO_LOCAL_DATE, i.e. exactly yyyy-MM-dd. It is the path Hibernate uses to read HQL/JPQL date literals and to convert string data into java.sql.Date. If the text does not match ISO local date (regional format, time part, whitespace), the DateTimeParseException is rethrown as HibernateException("could not parse date string ...").

Source

Thrown at hibernate-core/src/main/java/org/hibernate/type/descriptor/java/JdbcDateJavaType.java:260

	private static TemporalAccessor fromDate(java.util.Date value) {
		return value instanceof java.sql.Date date
				? date.toLocalDate()
				: LocalDate.ofInstant( value.toInstant(), ZoneOffset.systemDefault() );
	}

	@Override
	public String toString(Date value) {
		return LITERAL_FORMATTER.format( fromDate( value ) );
	}

	@Override
	public Date fromString(CharSequence string) {
		try {
			final var temporalAccessor = LITERAL_FORMATTER.parse( string );
			return java.sql.Date.valueOf( temporalAccessor.query( LocalDate::from ) );
		}
		catch ( DateTimeParseException pe) {
			throw new HibernateException( "could not parse date string " + string, pe );
		}
	}

	@Override
	public Date fromEncodedString(CharSequence charSequence, int start, int end) {
		try {
			final var temporalAccessor = ENCODED_FORMATTER.parse( subSequence( charSequence, start, end ) );
			return java.sql.Date.valueOf( temporalAccessor.query( LocalDate::from ) );
		}
		catch ( DateTimeParseException pe) {
			throw new HibernateException( "could not parse time string " + subSequence( charSequence, start, end ), pe );
		}
	}

	@Override
	public void appendEncodedString(SqlAppender sb, Date value) {
		LITERAL_FORMATTER.formatTo( fromDate( value ), sb );
	}

View on GitHub (pinned to fad1729dce)

Solutions

Rewrite literals and stored text to ISO format yyyy-MM-dd before Hibernate sees them
In HQL, prefer bind parameters of type LocalDate or java.sql.Date over string literals
For a text column holding dates in a fixed non-ISO format, add a javax.persistence.AttributeConverter that parses with the matching DateTimeFormatter
Trim/clean the incoming strings; reject empty strings before they reach the parser

Example fix

// before
em.createQuery("select e from Event e where e.day = '31/12/2024'") // HibernateException

// after
em.createQuery("select e from Event e where e.day = '2024-12-31'")
// or: query.setParameter("day", LocalDate.of(2024,12,31));

Defensive patterns

Strategy: validation

Validate before calling

static boolean isIsoDate(CharSequence s) {
    if (s == null) return false;
    try { java.time.LocalDate.parse(s); return true; }
    catch (java.time.format.DateTimeParseException e) { return false; }
}

// before binding/storing:
if (!isIsoDate(text)) throw new IllegalArgumentException("Expected yyyy-MM-dd: " + text);

Type guard

static java.time.LocalDate tryIsoDate(String s) {
    try { return java.time.LocalDate.parse(s.trim()); } catch (Exception e) { return null; }
}

Try / catch

try {
    Date d = JdbcDateJavaType.INSTANCE.fromString(text);
} catch (HibernateException e) {
    if (e.getCause() instanceof DateTimeParseException pe)
        throw new IllegalArgumentException("Bad date text: '" + text + "' (expected yyyy-MM-DD)", e);
    throw e;
}

Prevention

Always bind typed LocalDate/java.sql.Date parameters instead of string literals
Normalize external date text to ISO with an explicit DateTimeFormatter at the boundary
Reject empty strings before they reach Hibernate parsing

When it happens

Trigger: An HQL literal such as ... where e.d = '31/12/2024' or '2024.12.31' (only '2024-12-31' parses); calling JdbcDateJavaType.INSTANCE.fromString(...) or JavaType.fromString on a non-ISO string; a String-typed source (native query result, varchar column, XML mapping) coerced into a java.sql.Date attribute with non-ISO content, including empty strings and values with trailing spaces.

Common situations: Data imported from CSV/Excel with regional date formats; native SQL queries returning dates as formatted strings; reports or integrations that hand-formatted dates with SimpleDateFormat('dd/MM/yyyy') before binding; upgrades where hand-written literals no longer parse.

Related errors

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/d01355b15e616653. Report an issue: GitHub.