time_formats.md

Time formats

IG uses three different date/time formats depending on the endpoint version. Don't reimplement this — use the helpers in src/time.rs.

Input formats per version

Version	Format	Example
v1	%Y:%m:%d-%H:%M:%S	2014:12:15-09:30:45
v2	%Y/%m/%d %H:%M:%S	2014/12/15 09:30:45
v3	%Y-%m-%dT%H:%M:%S	2014-12-15T09:30:45

Output formats

Output formats vary even within a single response:

• v3 prices include both snapshotTime (v2-shaped) and snapshotTimeUTC (ISO-8601).
• v3 activity / transactions use ISO-8601 (%Y-%m-%dT%H:%M:%S).
• v1/v2 endpoints use their input format on output too.

Helpers

use crate::time::{ApiVersion, format, parse};

let s = format(dt, ApiVersion::V2);            // "2014/12/15 09:30:45"
let dt = parse(&s, ApiVersion::V2)?;

parse falls back to ISO-8601 if the version-specific format fails — useful when an endpoint returns mixed shapes.

In serde models

For response fields, prefer chrono::NaiveDateTime and add a custom #[serde(deserialize_with = "...")] only when the wire format isn't the chrono default. For most v3 responses, the default ISO-8601 deserializer works.

For v1/v2 fields where the wire format is non-standard, write a small helper module:

mod ig_v2_dt {
    use chrono::NaiveDateTime;
    use serde::{Deserialize, Deserializer, Serializer};
    pub fn serialize<S: Serializer>(dt: &NaiveDateTime, s: S) -> Result<S::Ok, S::Error> {
        s.serialize_str(&crate::time::format(*dt, crate::time::ApiVersion::V2))
    }
    pub fn deserialize<'de, D: Deserializer<'de>>(d: D) -> Result<NaiveDateTime, D::Error> {
        let s = String::deserialize(d)?;
        crate::time::parse(&s, crate::time::ApiVersion::V2)
            .map_err(serde::de::Error::custom)
    }
}

#[serde(with = "ig_v2_dt")]
pub created_date: NaiveDateTime,

Place these helpers next to the model struct that uses them, or move them to src/time.rs if reused across domains.