hphp/hack/manual/apis/Classes/IntlDatePatternGenerator/setAppendItemFormat.md
:::info[Note] This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information. :::
An append item format is a pattern used to append a field if there is no good match
public function setAppendItemFormat(
int $field,
string $value,
): void;
For example, suppose that the input skeleton is "GyyyyMMMd", and there is no matching pattern internally, but there is a pattern matching "yyyyMMMd", say "d-MM-yyyy". Then that pattern is used, plus the G. The way these two are conjoined is by using the AppendItemFormat for G (era). So if that value is, say "{0}, {1}" then the final resulting pattern is "d-MM-yyyy, G".
There are actually three available variables: {0} is the pattern so far, {1} is the element we are adding, and {2} is the name of the element.
int $field - Pattern field (see constants)string $value - Pattern, such as "{0}, {1}"void