Informix Error -1206: Invalid day in date.

Reasons / Common Causes

-1206 fires when a DATE value or literal's day component is invalid — per the official guidance, the day must be a one- or two-digit number from 1 to 28 (or 29 in a leap year), 30, or 31, depending on the accompanying month.

1. A day value outside the valid range for its month, per the official guidance — for example, day 31 with a 30-day month, or day 30 with February.
2. February 29 used in a non-leap year, per the official guidance's specific leap-year framing.
3. A DATE value computed or parsed with an out-of-range day, from a malformed source string or a date-arithmetic error.

Solutions / Resolution

1. Correct the day to a value valid for its month (and, for February 29, for the year), per the official guidance.
2. Check the source of the date value (a literal, a parsed string, or a computed expression) for where the invalid day originated.

Examples

An invalid day for the month

INSERT INTO orders (order_id, order_date) VALUES (1, '02/30/2024');
-- -1206: February has no 30th day

Corrected

INSERT INTO orders (order_id, order_date) VALUES (1, '02/29/2024');
-- valid: 2024 is a leap year

Diagnostic Checks

1. Check the day component against the valid range for its month and year, and trace back to wherever it was computed or parsed if it's not a literal typo.

Related Errors / Related Topics

• -1204 — "Invalid year in date." A related date-validity error, about the year component rather than the day.
• -1205 — "Invalid month in date." A related date-validity error, about the month component rather than the day.

The date's day component fell outside the valid range for its month (or February 29 in a non-leap year) — correct it, or trace back to where it was computed/parsed.