fix(coding-agent): keep only ISO date in system prompt closes #2131

packages/coding-agent/CHANGELOG.md

@@ -7,6 +7,7 @@
 - Fixed interactive input fields backed by the TUI `Input` component to scroll by visual column width for wide Unicode text (CJK, fullwidth characters), preventing rendered line overflow and TUI crashes in places like search and filter inputs ([#1982](https://github.com/badlogic/pi-mono/issues/1982))
 - Fixed `shift+tab` and other modified Tab bindings in tmux when `extended-keys-format` is left at the default `xterm`
 - Fixed EXIF orientation not being applied during image convert and resize, causing JPEG and WebP images from phone cameras to display rotated or mirrored ([#2105](https://github.com/badlogic/pi-mono/pull/2105) by [@melihmucuk](https://github.com/melihmucuk))
+- Fixed the default coding-agent system prompt to include only the current date in ISO format, not the current time, so prompt prefixes stay cacheable across reloads and resumed sessions ([#2131](https://github.com/badlogic/pi-mono/issues/2131))
 
 ## [0.57.1] - 2026-03-07
 

packages/coding-agent/src/core/system-prompt.ts

@@ -49,17 +49,7 @@ export function buildSystemPrompt(options: BuildSystemPromptOptions = {}): strin
 	} = options;
 	const resolvedCwd = cwd ?? process.cwd();
 
-	const now = new Date();
-	const dateTime = now.toLocaleString("en-US", {
-		weekday: "long",
-		year: "numeric",
-		month: "long",
-		day: "numeric",
-		hour: "2-digit",
-		minute: "2-digit",
-		second: "2-digit",
-		timeZoneName: "short",
-	});
+	const date = new Date().toISOString().slice(0, 10);
 
 	const appendSection = appendSystemPrompt ? `\n\n${appendSystemPrompt}` : "";
 
@@ -88,8 +78,8 @@ export function buildSystemPrompt(options: BuildSystemPromptOptions = {}): strin
 			prompt += formatSkillsForPrompt(skills);
 		}
 
-		// Add date/time and working directory last
-		prompt += `\nCurrent date and time: ${dateTime}`;
+		// Add date and working directory last
+		prompt += `\nCurrent date: ${date}`;
 		prompt += `\nCurrent working directory: ${resolvedCwd}`;
 
 		return prompt;
@@ -210,8 +200,8 @@ Pi documentation (read only when the user asks about pi itself, its SDK, extensi
 		prompt += formatSkillsForPrompt(skills);
 	}
 
-	// Add date/time and working directory last
-	prompt += `\nCurrent date and time: ${dateTime}`;
+	// Add date and working directory last
+	prompt += `\nCurrent date: ${date}`;
 	prompt += `\nCurrent working directory: ${resolvedCwd}`;
 
 	return prompt;