Informix Error -1218: String to date conversion error.

Reasons / Common Causes

-1218 fires when the input to rstrdate() doesn't properly represent a date — per the official guidance, this covers non-digit characters where digits are expected, an unexpected delimiter, or numbers that are too large or internally inconsistent (e.g. a day that doesn't fit its month).

1. Non-digit characters in the input where digits are expected, per the official guidance — the direct, named cause.
2. An unexpected delimiter in the input string, per the official guidance's other named cause.
3. Numbers too large, or inconsistent with each other (e.g. day 31 for a 30-day month), per the official guidance — the same underlying validity issues as -1204/-1205/-1206, surfaced through rstrdate()'s own parsing.

Solutions / Resolution

1. Validate the input string's format before passing it to rstrdate(), per the official guidance — check for non-digit characters, unexpected delimiters, and internally consistent month/day/year values.

Examples

Malformed input to rstrdate

int rc = rstrdate("13/45/2024", &date_val);
-- -1218: month 13 and day 45 are both invalid

Diagnostic Checks

1. Inspect the exact input string passed to rstrdate() for non-digit characters, unexpected delimiters, or an internally inconsistent month/day/year combination.

Related Errors / Related Topics

• -1204 — "Invalid year in date." A related date-validity error, in the general SQL date- literal context rather than rstrdate() specifically.
• -1205 — "Invalid month in date." A related date-validity error.
• -1206 — "Invalid day in date." A related date-validity error.
• -1209 — "Without any delimiters, this date must contain exactly 6 or 8 digits." A related date-parsing error, about undelimited numeric dates specifically.

rstrdate()'s input string doesn't properly represent a date — check for non-digit characters, unexpected delimiters, and internal month/day/year consistency.