How to fix Invalid argument for SQL/JSON datetime function in PostgreSQL

PostgreSQLINTERMEDIATEMEDIUMUpdated Dec 27, 2025· 104 views

This error occurs when the .datetime() method in PostgreSQL jsonpath expressions receives a string that cannot be parsed as a valid date/time format. Fix it by ensuring ISO 8601 format, using the silent parameter, or specifying a datetime template.

Quick fix

Fixes Invalid argument for SQL/JSON datetime function

-- This works (ISO 8601)
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00"', '$.datetime()');

-- This fails if "Z" is included without proper handling
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00Z"', '$.datetime()');
  1. Verify the input string format
  2. Use the silent parameter to suppress errors
  3. Use the @? or @@ operators for existence checks
  4. Specify a datetime template for non-standard formats
postgresql — error
-- This works (ISO 8601)
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00"', '$.datetime()');
-- This fails if "Z" is included without proper handling
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00Z"', '$.datetime()');
Invalid argument for SQL/JSON datetime function

What this error means

The SQL/JSON path datetime() function is designed to convert valid date and time strings (such as ISO 8601 format) into their corresponding PostgreSQL datetime types. This error is raised when the input string does not match any recognized datetime format that PostgreSQL can parse. The datetime() method is particularly strict about format compliance and timezone indicators. In PostgreSQL 12 and earlier, the .datetime() method was not fully implemented due to immutable jsonpath functions being unable to reference session timezone, which is used in some datetime operations. Starting with PostgreSQL 13, support improved but format requirements remain strict. Non-standard date formats, invalid timezone indicators (like "Z" when not expected), or malformed timestamps will trigger this error.

Typical symptoms

  • jsonb_path_query() or similar functions fail with datetime error messages
  • Queries using .datetime() in jsonpath expressions return errors instead of results
  • Converting timestamp values stored in JSONB to datetime types fails
  • Applications fail when attempting to filter or compare dates extracted from JSON
  • Error appears during data transformation or migration operations involving JSON dates

Common causes

  1. Input string is not in ISO 8601 format or another recognized PostgreSQL datetime format
  2. Timezone indicator "Z" is present in the string when PostgreSQL expects a numeric offset
  3. String contains invalid characters or separators not allowed in datetime format strings
  4. Using .datetime() with non-string JSON values (arrays, objects, numbers)
  5. PostgreSQL version 12 or earlier where .datetime() is not fully implemented
  6. Format string in datetime() template contains invalid separator characters
  7. Attempting to compare timezone-aware and non-timezone-aware datetime values

How to fix "Invalid argument for SQL/JSON datetime function"

1Verify the input string format

Check that the datetime string is in ISO 8601 format. PostgreSQL expects dates in the format YYYY-MM-DD and times in HH:MM:SS.

sql
-- This works (ISO 8601)
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00"', '$.datetime()');

-- This fails if "Z" is included without proper handling
SELECT jsonb_path_query(jsonb '"2023-12-25T10:30:00Z"', '$.datetime()');
2Use the silent parameter to suppress errors

If you want to suppress datetime errors (useful for data with mixed formats), use the jsonb_path_query() function with the silent parameter set to true:

sql
-- Suppress datetime errors
SELECT jsonb_path_query(data, '$.datetime()', silent => true)
FROM your_table;

This will return NULL for values that cannot be parsed as datetime instead of raising an error.

3Use the @? or @@ operators for existence checks

The @? (existence) and @@ (match) jsonpath operators automatically suppress datetime errors, making them useful for conditional checks:

sql
-- Check if a datetime path exists without throwing errors
SELECT * FROM your_table
WHERE data @? '$.timestamp.datetime()';
4Specify a datetime template for non-standard formats

If your JSON contains dates in a non-standard format, provide a datetime template string to specify the expected format:

sql
-- Parse dates in DD/MM/YYYY format
SELECT jsonb_path_query(
  jsonb '"25/12/2023"',
  '$.datetime("DD/MM/YYYY")'
);

-- Parse dates with timezone offset
SELECT jsonb_path_query(
  jsonb '"2023-12-25T10:30:00+02:00"',
  '$.datetime()'
);
5Cast JSONB datetime strings to timestamp type

As a workaround, extract the string from JSONB and cast it to timestamp, rather than using .datetime():

sql
-- Instead of using .datetime()
SELECT (data->>'timestamp')::timestamp
FROM your_table;

-- For timezone-aware timestamps
SELECT (data->>'timestamp')::timestamptz
FROM your_table;
6Ensure compatibility with PostgreSQL 13+

If you are running PostgreSQL 12, consider upgrading to PostgreSQL 13 or later where datetime() support is more complete. If upgrade is not possible, rely on the workarounds above (casting to timestamp types, using operators that suppress errors, or pre-processing JSON before querying).

Advanced notes

The datetime() method in jsonpath is governed by the SQL/JSON standard, but PostgreSQL has historically deferred full compliance due to immutable function constraints. Starting with PostgreSQL 13, timezone-aware variants (jsonb_path_*_tz functions) were introduced to support full datetime comparison features. When working with timezone-aware timestamps, prefer these stable functions over the immutable variants. Additionally, understand that datetime values in SQL/JSON are stored internally as strings and only converted during comparison operations—they do not occupy separate storage space. This design choice influences performance and storage considerations in systems handling large volumes of datetime JSON data.

Frequently asked questions

What does "Invalid argument for SQL/JSON datetime function" mean?
The SQL/JSON path datetime() function is designed to convert valid date and time strings (such as ISO 8601 format) into their corresponding PostgreSQL datetime types. This error is raised when the input string does not match any recognized datetime format that PostgreSQL can parse. The datetime() method is particularly strict about format compliance and timezone indicators.
How do I fix "Invalid argument for SQL/JSON datetime function"?
This error occurs when the .datetime() method in PostgreSQL jsonpath expressions receives a string that cannot be parsed as a valid date/time format. Fix it by ensuring ISO 8601 format, using the silent parameter, or specifying a datetime template.
What causes "Invalid argument for SQL/JSON datetime function"?
Input string is not in ISO 8601 format or another recognized PostgreSQL datetime format Timezone indicator "Z" is present in the string when PostgreSQL expects a numeric offset String contains invalid characters or separators not allowed in datetime format strings
Is the "Invalid argument for SQL/JSON datetime function" error serious?
It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

Official resources & further reading