Function deserialize 

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

Reads null, an empty text and the epoch text as None, and any other date-time as Some.

Errors

A serde error if the text is not a date-time in the forms super::deserialize accepts.