From 316fe71133ef94b75321c5c1d2e92fe599d1109d Mon Sep 17 00:00:00 2001
From: Shannon Sterz <s.sterz@proxmox.com>
Date: Tue, 4 Mar 2025 15:42:27 +0100
Subject: [PATCH] time: add new `epoch_to_http_date` helper

this makes it easy to generate RFC9110 preferred HTTP Dates.

Signed-off-by: Shannon Sterz <s.sterz@proxmox.com>
---
 proxmox-time/src/posix.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/proxmox-time/src/posix.rs b/proxmox-time/src/posix.rs
index bb60ba04..79fcb1b6 100644
--- a/proxmox-time/src/posix.rs
+++ b/proxmox-time/src/posix.rs
@@ -380,6 +380,15 @@ pub fn epoch_to_rfc2822(epoch: i64) -> Result<String, Error> {
     Ok(rfc2822_date)
 }
 
+/// Convert an epoch to an RFC9110 preferred HTTP Date format.
+///
+/// see: <https://httpwg.org/specs/rfc9110.html#http.date>
+pub fn epoch_to_http_date(epoch: i64) -> Result<String, Error> {
+    let gmtime = gmtime(epoch)?;
+    let locale = Locale::new(libc::LC_ALL, Locale::C)?;
+    strftime_l("%a, %d %b %Y %H:%M:%S GMT", &gmtime, &locale)
+}
+
 #[test]
 fn test_leap_seconds() {
     let convert_reconvert = |epoch| {