add time format string util

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

Cargo.toml

@@ -208,7 +208,7 @@ features = ["serde"]
 # standard date and time tools
 [workspace.dependencies.chrono]
 version = "0.4.38"
-features = ["alloc"]
+features = ["alloc", "std"]
 default-features = false
 
 [workspace.dependencies.hyper]

src/core/utils/time.rs

@@ -1,9 +1,9 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
 #[inline]
 #[must_use]
 #[allow(clippy::as_conversions)]
 pub fn now_millis() -> u64 {
-	use std::time::UNIX_EPOCH;
-
 	UNIX_EPOCH
 		.elapsed()
 		.expect("positive duration after epoch")
@@ -18,3 +18,11 @@ pub fn rfc2822_from_seconds(epoch: i64) -> String {
 		.unwrap_or_default()
 		.to_rfc2822()
 }
+
+#[must_use]
+pub fn format(ts: SystemTime, str: &str) -> String {
+	use chrono::{DateTime, Utc};
+
+	let dt: DateTime<Utc> = ts.into();
+	dt.format(str).to_string()
+}