pub const DATE_FORMAT: &str = "%Y-%m-%d";Expand description
The wire format a FieldKind::Date value takes: ISO 8601, YYYY-MM-DD.
A constant rather than a sentence in a doc comment, because the reason to name the format at all is that a host picking its own would fail silently against a server parsing another. A host that cannot emit the native control still has one spelling to meet, and can say which one it meant.