diff --git a/rustfs/src/storage/ecfs_extend.rs b/rustfs/src/storage/ecfs_extend.rs
index f521e32cb..38bd59749 100644
--- a/rustfs/src/storage/ecfs_extend.rs
+++ b/rustfs/src/storage/ecfs_extend.rs
@@ -47,10 +47,14 @@ use std::collections::HashMap;
 use std::ops::Add;
 use std::sync::Arc;
 use time::OffsetDateTime;
-use time::format_description::well_known::{Rfc2822, Rfc3339};
+use time::format_description::well_known::Rfc3339;
+use time::{format_description::FormatItem, macros::format_description};
 use tokio::io::AsyncRead;
 use tracing::{debug, warn};
 
+const RFC1123: &[FormatItem<'_>] =
+    format_description!("[weekday repr:short], [day] [month repr:short] [year] [hour]:[minute]:[second] GMT");
+
 /// =======================
 /// Presigned POST helpers
 /// =======================
@@ -614,7 +618,7 @@ pub(crate) async fn validate_bucket_object_lock_enabled(bucket: &str) -> S3Resul
 }
 
 /// Validates HTTP conditional request headers for a single object according to
-/// RFC 7232 and S3 API semantics.
+/// RFC 7232 (HTTP/1.1 conditional requests) and S3 API semantics.
 ///
 /// This function evaluates the following headers, if present, in the standard
 /// conditional request order:
@@ -654,7 +658,7 @@ pub(crate) fn check_preconditions(headers: &HeaderMap, info: &ObjectInfo) -> S3R
     if headers.get("if-match").is_none()
         && let Some(t) = mod_time
         && let Some(if_unmodified_since) = headers.get("if-unmodified-since").and_then(|v| v.to_str().ok())
-        && let Ok(given_time) = OffsetDateTime::parse(if_unmodified_since, &Rfc2822)
+        && let Ok(given_time) = time::PrimitiveDateTime::parse(if_unmodified_since, &RFC1123).map(|dt| dt.assume_utc())
         && t > given_time.add(time::Duration::seconds(1))
     {
         return Err(S3Error::new(S3ErrorCode::PreconditionFailed));
@@ -670,7 +674,7 @@ pub(crate) fn check_preconditions(headers: &HeaderMap, info: &ObjectInfo) -> S3R
             error_headers.insert("etag", etag_header);
         }
         if let Some(t) = mod_time
-            && let Ok(last_modified_str) = t.format(&Rfc2822)
+            && let Ok(last_modified_str) = t.format(&RFC1123)
             && let Ok(last_modified_header) = HeaderValue::from_str(&last_modified_str)
         {
             error_headers.insert("last-modified", last_modified_header);
@@ -683,11 +687,11 @@ pub(crate) fn check_preconditions(headers: &HeaderMap, info: &ObjectInfo) -> S3R
         return Err(s3_error);
     }
 
-    // If-Modified-Since (only when If-None-Match is absent - RFC 7232)
+    // If-Modified-Since (only when If-None-Match is absent — semantics per RFC 7232; dates use RFC 1123 format)
     if headers.get("if-none-match").is_none()
         && let Some(t) = mod_time
         && let Some(if_modified_since) = headers.get("if-modified-since").and_then(|v| v.to_str().ok())
-        && let Ok(given_time) = OffsetDateTime::parse(if_modified_since, &Rfc2822)
+        && let Ok(given_time) = time::PrimitiveDateTime::parse(if_modified_since, &RFC1123).map(|dt| dt.assume_utc())
         && t < given_time.add(time::Duration::seconds(1))
     {
         let mut error_headers = HeaderMap::new();
@@ -696,7 +700,7 @@ pub(crate) fn check_preconditions(headers: &HeaderMap, info: &ObjectInfo) -> S3R
         {
             error_headers.insert("etag", etag_header);
         }
-        if let Ok(last_modified_str) = t.format(&Rfc2822)
+        if let Ok(last_modified_str) = t.format(&RFC1123)
             && let Ok(last_modified_header) = HeaderValue::from_str(&last_modified_str)
         {
             error_headers.insert("last-modified", last_modified_header);
diff --git a/rustfs/src/storage/ecfs_test.rs b/rustfs/src/storage/ecfs_test.rs
index 305619694..d282a398e 100644
--- a/rustfs/src/storage/ecfs_test.rs
+++ b/rustfs/src/storage/ecfs_test.rs
@@ -35,7 +35,6 @@ mod tests {
     };
     use s3s::{S3Error, S3ErrorCode, s3_error};
     use time::OffsetDateTime;
-    use time::format_description::well_known::Rfc2822;
 
     #[test]
     fn test_fs_creation() {
@@ -558,6 +557,9 @@ mod tests {
 
     #[test]
     fn test_check_preconditions() {
+        use time::{format_description::FormatItem, macros::format_description};
+        const RFC1123: &[FormatItem<'_>] =
+            format_description!("[weekday repr:short], [day] [month repr:short] [year] [hour]:[minute]:[second] GMT");
         let valid_mod_time = OffsetDateTime::from_unix_timestamp(1700000000).unwrap();
         let valid_etag = "\"d41d8cd98f00b204e9800998ecf8427e\"";
         let wrong_etag = "\"wrong-etag-123456\"";
@@ -605,7 +607,7 @@ mod tests {
         let mut headers5 = HeaderMap::new();
         headers5.insert(
             "if-modified-since",
-            HeaderValue::from_str(&valid_mod_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&valid_mod_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info5 = info3.clone();
         let result5 = check_preconditions(&headers5, &info5);
@@ -618,7 +620,7 @@ mod tests {
         let mut headers6 = HeaderMap::new();
         headers6.insert(
             "if-modified-since",
-            HeaderValue::from_str(&earlier_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&earlier_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info6 = info3.clone();
         assert!(check_preconditions(&headers6, &info6).is_ok());
@@ -641,7 +643,7 @@ mod tests {
         let mut headers9 = HeaderMap::new();
         headers9.insert(
             "if-unmodified-since",
-            HeaderValue::from_str(&earlier_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&earlier_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info9 = info3.clone();
         let result9 = check_preconditions(&headers9, &info9);
@@ -652,7 +654,7 @@ mod tests {
         let mut headers10 = HeaderMap::new();
         headers10.insert(
             "if-unmodified-since",
-            HeaderValue::from_str(&valid_mod_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&valid_mod_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info10 = info3.clone();
         assert!(check_preconditions(&headers10, &info10).is_ok());
@@ -684,7 +686,7 @@ mod tests {
         headers13.insert("if-none-match", HeaderValue::from_str(valid_etag).unwrap());
         headers13.insert(
             "if-modified-since",
-            HeaderValue::from_str(&earlier_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&earlier_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info13 = info3.clone();
         let result13 = check_preconditions(&headers13, &info13);
@@ -696,7 +698,7 @@ mod tests {
         headers14.insert("if-none-match", HeaderValue::from_str("\"wrong-etag\"").unwrap());
         headers14.insert(
             "if-modified-since",
-            HeaderValue::from_str(&valid_mod_time.format(&Rfc2822).unwrap()).unwrap(),
+            HeaderValue::from_str(&valid_mod_time.format(&RFC1123).unwrap()).unwrap(),
         );
         let info14 = info3.clone();
         assert!(check_preconditions(&headers14, &info14).is_ok());