Function deserialize 

pub fn deserialize<'de, D>(deserializer: D) -> Result<DateTime<Utc>, D::Error>
where
    D: Deserializer<'de>,

Reads an RFC 3339 text or the plain YYYY-MM-DDTHH:MM:SS.mmmZ text into a UTC date-time.

Errors

A serde error if the text is not a date-time in one of those forms.