diff --git a/crates/openshell-cli/src/commands/common.rs b/crates/openshell-cli/src/commands/common.rs
index 49fd66a9a8..99db81eca5 100644
--- a/crates/openshell-cli/src/commands/common.rs
+++ b/crates/openshell-cli/src/commands/common.rs
@@ -140,22 +140,6 @@ pub fn format_timestamp(d: Duration) -> String {
     format!("[{secs:.1}s]")
 }
 
-/// Format a millisecond timestamp into a readable string.
-pub fn format_timestamp_ms(ms: i64) -> String {
-    if ms <= 0 {
-        return "-".to_string();
-    }
-    let secs = ms / 1000;
-    let mins = (secs / 60) % 60;
-    let hours = (secs / 3600) % 24;
-    let days = secs / 86400;
-    if days > 0 {
-        format!("{days}d {hours:02}:{mins:02}")
-    } else {
-        format!("{hours:02}:{mins:02}")
-    }
-}
-
 pub fn truncate_status_field(value: &str, max_chars: usize) -> String {
     if value.is_empty() {
         return "-".to_string();
@@ -1072,6 +1056,20 @@ pub fn scrub_git_env(command: &mut Command) -> &mut Command {
 mod tests {
     use super::*;
 
+    #[test]
+    fn optional_epoch_ms_renders_absolute_date_not_day_count() {
+        // Rule-history entries carry an absolute `google.protobuf.Timestamp`
+        // (epoch ms), so the rendered string must be a readable wall-clock
+        // date, never a days-since-epoch count. 1_700_000_000_000 ms is
+        // 2023-11-14T22:13:20Z.
+        assert_eq!(
+            format_optional_epoch_ms(1_700_000_000_000),
+            "2023-11-14 22:13:20"
+        );
+        // A missing timestamp (proto default -> 0 ms) renders as a placeholder.
+        assert_eq!(format_optional_epoch_ms(0), "-");
+    }
+
     #[test]
     fn parse_duration_to_ms_parses_supported_units() {
         assert_eq!(parse_duration_to_ms("30s").expect("parse"), 30_000);
diff --git a/crates/openshell-cli/src/run.rs b/crates/openshell-cli/src/run.rs
index 3aa775685f..c188b7b10d 100644
--- a/crates/openshell-cli/src/run.rs
+++ b/crates/openshell-cli/src/run.rs
@@ -9,10 +9,10 @@ pub use crate::commands::common::{
 };
 use crate::commands::common::{
     ProvisioningDisplay, ProvisioningStep, confirm_global_setting_delete,
-    confirm_global_setting_takeover, format_epoch_ms, format_setting_value, format_timestamp,
-    format_timestamp_ms, handle_platform_progress_event, is_provisioning_progress_event,
-    non_empty_or, parse_cli_setting_value, parse_duration_to_ms, phase_name,
-    print_policy_merge_warnings, print_sandbox_header, print_sandbox_policy,
+    confirm_global_setting_takeover, format_epoch_ms, format_optional_epoch_ms,
+    format_setting_value, format_timestamp, handle_platform_progress_event,
+    is_provisioning_progress_event, non_empty_or, parse_cli_setting_value, parse_duration_to_ms,
+    phase_name, print_policy_merge_warnings, print_sandbox_header, print_sandbox_policy,
     provisioning_timeout_message, ready_false_condition_message, scrub_git_env, short_hash,
     truncate_status_field,
 };
@@ -6588,7 +6588,7 @@ pub async fn sandbox_draft_history(
 
         println!(
             "  {} {} [{}] {}",
-            format_timestamp_ms(proto_timestamp_ms(entry.event_time.as_ref())).dimmed(),
+            format_optional_epoch_ms(proto_timestamp_ms(entry.event_time.as_ref())).dimmed(),
             event_colored,
             entry.chunk_id.get(..8).unwrap_or(&entry.chunk_id),
             entry.description,