feat(date-time): standardize time context and tool timestamps

src/agents/system-prompt.ts

@@ -1,6 +1,7 @@
 import type { ReasoningLevel, ThinkLevel } from "../auto-reply/thinking.js";
 import { SILENT_REPLY_TOKEN } from "../auto-reply/tokens.js";
 import { listDeliverableMessageChannels } from "../utils/message-channel.js";
+import type { ResolvedTimeFormat } from "./date-time.js";
 import type { EmbeddedContextFile } from "./pi-embedded-helpers.js";
 
 export function buildAgentSystemPrompt(params: {
@@ -15,6 +16,7 @@ export function buildAgentSystemPrompt(params: {
   modelAliasLines?: string[];
   userTimezone?: string;
   userTime?: string;
+  userTimeFormat?: ResolvedTimeFormat;
   contextFiles?: EmbeddedContextFile[];
   skillsPrompt?: string;
   heartbeatPrompt?: string;
@@ -312,17 +314,21 @@ export function buildAgentSystemPrompt(params: {
     ownerLine ? "## User Identity" : "",
     ownerLine ?? "",
     ownerLine ? "" : "",
+    ...(userTimezone || userTime
+      ? [
+          "## Current Date & Time",
+          userTime
+            ? `${userTime} (${userTimezone ?? "unknown"})`
+            : `Time zone: ${userTimezone}. Current time unknown; assume UTC for date/time references.`,
+          params.userTimeFormat
+            ? `Time format: ${params.userTimeFormat === "24" ? "24-hour" : "12-hour"}`
+            : "",
+          "",
+        ]
+      : []),
     "## Workspace Files (injected)",
     "These user-editable files are loaded by Clawdbot and included below in Project Context.",
     "",
-    userTimezone || userTime
-      ? `Time: assume UTC unless stated. User time zone: ${
-          userTimezone ?? "unknown"
-        }. Current user time (local, 24-hour): ${userTime ?? "unknown"} (${
-          userTimezone ?? "unknown"
-        }).`
-      : "",
-    userTimezone || userTime ? "" : "",
     "## Reply Tags",
     "To request a native reply/quote on supported surfaces, include one tag in your reply:",
     "- [[reply_to_current]] replies to the triggering message.",