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

src/agents/pi-embedded-runner/compact.ts

@@ -53,12 +53,11 @@ import { prewarmSessionFile, trackSessionManagerAccess } from "./session-manager
 import { buildEmbeddedSystemPrompt, createSystemPromptOverride } from "./system-prompt.js";
 import { splitSdkTools } from "./tool-split.js";
 import type { EmbeddedPiCompactResult } from "./types.js";
+import { formatUserTime, resolveUserTimeFormat, resolveUserTimezone } from "../date-time.js";
 import {
   describeUnknownError,
-  formatUserTime,
   mapThinkingLevel,
   resolveExecToolDefaults,
-  resolveUserTimezone,
 } from "./utils.js";
 
 export async function compactEmbeddedPiSession(params: {
@@ -228,7 +227,10 @@ export async function compactEmbeddedPiSession(params: {
         const sandboxInfo = buildEmbeddedSandboxInfo(sandbox, params.bashElevated);
         const reasoningTagHint = isReasoningTagProvider(provider);
         const userTimezone = resolveUserTimezone(params.config?.agents?.defaults?.userTimezone);
-        const userTime = formatUserTime(new Date(), userTimezone);
+        const userTimeFormat = resolveUserTimeFormat(
+          params.config?.agents?.defaults?.timeFormat,
+        );
+        const userTime = formatUserTime(new Date(), userTimezone, userTimeFormat);
         const { defaultAgentId, sessionAgentId } = resolveSessionAgentIds({
           sessionKey: params.sessionKey,
           config: params.config,
@@ -251,6 +253,7 @@ export async function compactEmbeddedPiSession(params: {
           modelAliasLines: buildModelAliasLines(params.config),
           userTimezone,
           userTime,
+          userTimeFormat,
           contextFiles,
         });
         const systemPrompt = createSystemPromptOverride(appendPrompt);

src/agents/pi-embedded-runner/run/attempt.ts

@@ -58,12 +58,8 @@ import { prewarmSessionFile, trackSessionManagerAccess } from "../session-manage
 import { prepareSessionManagerForRun } from "../session-manager-init.js";
 import { buildEmbeddedSystemPrompt, createSystemPromptOverride } from "../system-prompt.js";
 import { splitSdkTools } from "../tool-split.js";
-import {
-  formatUserTime,
-  mapThinkingLevel,
-  resolveExecToolDefaults,
-  resolveUserTimezone,
-} from "../utils.js";
+import { formatUserTime, resolveUserTimeFormat, resolveUserTimezone } from "../../date-time.js";
+import { mapThinkingLevel, resolveExecToolDefaults } from "../utils.js";
 import { resolveSandboxRuntimeStatus } from "../../sandbox/runtime-status.js";
 
 import type { EmbeddedRunAttemptParams, EmbeddedRunAttemptResult } from "./types.js";
@@ -186,7 +182,8 @@ export async function runEmbeddedAttempt(
     const sandboxInfo = buildEmbeddedSandboxInfo(sandbox, params.bashElevated);
     const reasoningTagHint = isReasoningTagProvider(params.provider);
     const userTimezone = resolveUserTimezone(params.config?.agents?.defaults?.userTimezone);
-    const userTime = formatUserTime(new Date(), userTimezone);
+    const userTimeFormat = resolveUserTimeFormat(params.config?.agents?.defaults?.timeFormat);
+    const userTime = formatUserTime(new Date(), userTimezone, userTimeFormat);
     const { defaultAgentId, sessionAgentId } = resolveSessionAgentIds({
       sessionKey: params.sessionKey,
       config: params.config,
@@ -211,6 +208,7 @@ export async function runEmbeddedAttempt(
       modelAliasLines: buildModelAliasLines(params.config),
       userTimezone,
       userTime,
+      userTimeFormat,
       contextFiles,
     });
     const systemPromptReport = buildSystemPromptReport({

src/agents/pi-embedded-runner/system-prompt.ts

@@ -1,4 +1,5 @@
 import type { AgentTool } from "@mariozechner/pi-agent-core";
+import type { ResolvedTimeFormat } from "../date-time.js";
 import type { EmbeddedContextFile } from "../pi-embedded-helpers.js";
 import { buildAgentSystemPrompt } from "../system-prompt.js";
 import { buildToolSummaryMap } from "../tool-summaries.js";
@@ -33,6 +34,7 @@ export function buildEmbeddedSystemPrompt(params: {
   modelAliasLines: string[];
   userTimezone: string;
   userTime?: string;
+  userTimeFormat?: ResolvedTimeFormat;
   contextFiles?: EmbeddedContextFile[];
 }): string {
   return buildAgentSystemPrompt({
@@ -52,6 +54,7 @@ export function buildEmbeddedSystemPrompt(params: {
     modelAliasLines: params.modelAliasLines,
     userTimezone: params.userTimezone,
     userTime: params.userTime,
+    userTimeFormat: params.userTimeFormat,
     contextFiles: params.contextFiles,
   });
 }

src/agents/pi-embedded-runner/utils.ts

@@ -17,45 +17,6 @@ export function resolveExecToolDefaults(config?: ClawdbotConfig): ExecToolDefaul
   return { ...tools.bash, ...tools.exec };
 }
 
-export function resolveUserTimezone(configured?: string): string {
-  const trimmed = configured?.trim();
-  if (trimmed) {
-    try {
-      new Intl.DateTimeFormat("en-US", { timeZone: trimmed }).format(new Date());
-      return trimmed;
-    } catch {
-      // ignore invalid timezone
-    }
-  }
-  const host = Intl.DateTimeFormat().resolvedOptions().timeZone;
-  return host?.trim() || "UTC";
-}
-
-export function formatUserTime(date: Date, timeZone: string): string | undefined {
-  try {
-    const parts = new Intl.DateTimeFormat("en-CA", {
-      timeZone,
-      weekday: "long",
-      year: "numeric",
-      month: "2-digit",
-      day: "2-digit",
-      hour: "2-digit",
-      minute: "2-digit",
-      hourCycle: "h23",
-    }).formatToParts(date);
-    const map: Record<string, string> = {};
-    for (const part of parts) {
-      if (part.type !== "literal") map[part.type] = part.value;
-    }
-    if (!map.weekday || !map.year || !map.month || !map.day || !map.hour || !map.minute) {
-      return undefined;
-    }
-    return `${map.weekday} ${map.year}-${map.month}-${map.day} ${map.hour}:${map.minute}`;
-  } catch {
-    return undefined;
-  }
-}
-
 export function describeUnknownError(error: unknown): string {
   if (error instanceof Error) return error.message;
   if (typeof error === "string") return error;