encap dep:chrono in time utils

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/utils/time.rs

@@ -9,3 +9,12 @@ pub fn millis_since_unix_epoch() -> u64 {
 		.expect("time is valid")
 		.as_millis() as u64
 }
+
+#[must_use]
+pub fn rfc2822_from_seconds(epoch: i64) -> String {
+	use chrono::{DateTime, Utc};
+
+	DateTime::<Utc>::from_timestamp(epoch, 0)
+		.unwrap_or_default()
+		.to_rfc2822()
+}