feat(agents): include full date with day of week in system prompt

Fixes #2108

The system prompt now displays the full current date and time when
userTime is available, including day of week (e.g., 'Monday, January 26th, 2026 — 15:30').
This eliminates day-of-week guessing errors where the agent would
confidently state the wrong day based on timestamp inference.

Changes:
- Modified buildTimeSection to accept and display userTime parameter
- Updated tests to verify userTime appears in system prompt
- Format: 'Current: <full date>' followed by 'Time zone: <timezone>'

CHANGELOG.md

@@ -6,6 +6,7 @@ Docs: https://docs.clawd.bot
 Status: unreleased.
 
 ### Changes
+- Agents: include full date with day of week in system prompt. (#2108)
 - Doctor: warn on gateway exposure without auth. (#2016) Thanks @Alex-Alaniz.
 - Docs: add Vercel AI Gateway to providers sidebar. (#1901) Thanks @jerilynzheng.
 - Agents: expand cron tool description with full schema docs. (#1988) Thanks @tomascupr.

src/agents/system-prompt.test.ts

@@ -145,6 +145,7 @@ describe("buildAgentSystemPrompt", () => {
     });
 
     expect(prompt).toContain("## Current Date & Time");
+    expect(prompt).toContain("Current: Monday, January 5th, 2026 — 3:26 PM");
     expect(prompt).toContain("Time zone: America/Chicago");
   });
 
@@ -157,6 +158,7 @@ describe("buildAgentSystemPrompt", () => {
     });
 
     expect(prompt).toContain("## Current Date & Time");
+    expect(prompt).toContain("Current: Monday, January 5th, 2026 — 15:26");
     expect(prompt).toContain("Time zone: America/Chicago");
   });
 

src/agents/system-prompt.ts

@@ -49,9 +49,15 @@ function buildUserIdentitySection(ownerLine: string | undefined, isMinimal: bool
   return ["## User Identity", ownerLine, ""];
 }
 
-function buildTimeSection(params: { userTimezone?: string }) {
+function buildTimeSection(params: { userTimezone?: string; userTime?: string }) {
   if (!params.userTimezone) return [];
-  return ["## Current Date & Time", `Time zone: ${params.userTimezone}`, ""];
+  const lines = ["## Current Date & Time"];
+  if (params.userTime) {
+    lines.push(`Current: ${params.userTime}`);
+  }
+  lines.push(`Time zone: ${params.userTimezone}`);
+  lines.push("");
+  return lines;
 }
 
 function buildReplyTagsSection(isMinimal: boolean) {
@@ -297,6 +303,7 @@ export function buildAgentSystemPrompt(params: {
     : undefined;
   const reasoningLevel = params.reasoningLevel ?? "off";
   const userTimezone = params.userTimezone?.trim();
+  const userTime = params.userTime?.trim();
   const skillsPrompt = params.skillsPrompt?.trim();
   const heartbeatPrompt = params.heartbeatPrompt?.trim();
   const heartbeatPromptLine = heartbeatPrompt
@@ -459,6 +466,7 @@ export function buildAgentSystemPrompt(params: {
     ...buildUserIdentitySection(ownerLine, isMinimal),
     ...buildTimeSection({
       userTimezone,
+      userTime,
     }),
     "## Workspace Files (injected)",
     "These user-editable files are loaded by Clawdbot and included below in Project Context.",