usechrono::{DateTime, Utc};/// ISO 8601 format used by most AWS APIs.
pubfniso8601(dt:&DateTime<Utc>)-> String{
dt.format("%Y-%m-%dT%H:%M:%S%.3fZ").to_string()}/// Epoch seconds, used by some AWS APIs.
pubfnepoch_seconds(dt:&DateTime<Utc>)->f64{
dt.timestamp()asf64+(dt.timestamp_subsec_millis()asf64/1000.0)}