Add {{timestamp}} built-in routine variable

Renders as a human-readable date and time in UTC (e.g. "April 28,
2026 at 12:17 PM UTC"), complementing the existing {{date}} variable.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/shared/src/routine-variables.test.ts

@@ -46,8 +46,10 @@ describe("routine variable helpers", () => {
 
   it("identifies built-in variable names", () => {
     expect(isBuiltinRoutineVariable("date")).toBe(true);
+    expect(isBuiltinRoutineVariable("timestamp")).toBe(true);
     expect(isBuiltinRoutineVariable("repo")).toBe(false);
     expect(BUILTIN_ROUTINE_VARIABLE_NAMES.has("date")).toBe(true);
+    expect(BUILTIN_ROUTINE_VARIABLE_NAMES.has("timestamp")).toBe(true);
   });
 
   it("getBuiltinRoutineVariableValues returns date in YYYY-MM-DD format", () => {
@@ -56,9 +58,17 @@ describe("routine variable helpers", () => {
     expect(values.date).toBe(new Date().toISOString().slice(0, 10));
   });
 
+  it("getBuiltinRoutineVariableValues returns a human-readable timestamp with year, time, and UTC", () => {
+    const values = getBuiltinRoutineVariableValues();
+    const year = String(new Date().getUTCFullYear());
+    expect(values.timestamp).toContain(year);
+    expect(values.timestamp).toMatch(/\d{1,2}:\d{2}\s?(AM|PM)/);
+    expect(values.timestamp).toContain("UTC");
+  });
+
   it("excludes built-in variables from syncRoutineVariablesWithTemplate", () => {
     const result = syncRoutineVariablesWithTemplate(
-      "Daily report for {{date}} — {{repo}}",
+      "Daily report for {{date}} at {{timestamp}} — {{repo}}",
       [],
     );
     expect(result).toEqual([
@@ -66,11 +76,11 @@ describe("routine variable helpers", () => {
     ]);
   });
 
-  it("interpolates built-in date variable alongside user variables", () => {
+  it("interpolates built-in variables alongside user variables", () => {
     const builtins = getBuiltinRoutineVariableValues();
     const allVars = { ...builtins, repo: "paperclip" };
     expect(
-      interpolateRoutineTemplate("Report for {{date}} on {{repo}}", allVars),
-    ).toBe(`Report for ${builtins.date} on paperclip`);
+      interpolateRoutineTemplate("Report for {{date}} ({{timestamp}}) on {{repo}}", allVars),
+    ).toBe(`Report for ${builtins.date} (${builtins.timestamp}) on paperclip`);
   });
 });

packages/shared/src/routine-variables.ts

@@ -7,19 +7,33 @@ type RoutineTemplateInput = string | null | undefined | Array<string | null | un
  * Built-in variable names that are automatically available in routine templates
  * without needing to be defined in the routine's variables list.
  */
-export const BUILTIN_ROUTINE_VARIABLE_NAMES = new Set(["date"]);
+export const BUILTIN_ROUTINE_VARIABLE_NAMES = new Set(["date", "timestamp"]);
 
 export function isBuiltinRoutineVariable(name: string): boolean {
   return BUILTIN_ROUTINE_VARIABLE_NAMES.has(name);
 }
 
+const HUMAN_TIMESTAMP_FORMATTER = new Intl.DateTimeFormat("en-US", {
+  year: "numeric",
+  month: "long",
+  day: "numeric",
+  hour: "numeric",
+  minute: "2-digit",
+  hour12: true,
+  timeZone: "UTC",
+  timeZoneName: "short",
+});
+
 /**
  * Returns current values for all built-in routine variables.
  * `date` expands to the current date in YYYY-MM-DD format (UTC).
+ * `timestamp` expands to a human-readable date and time (e.g. "April 28, 2026 at 12:17 PM UTC").
  */
 export function getBuiltinRoutineVariableValues(): Record<string, string> {
+  const now = new Date();
   return {
-    date: new Date().toISOString().slice(0, 10),
+    date: now.toISOString().slice(0, 10),
+    timestamp: HUMAN_TIMESTAMP_FORMATTER.format(now),
   };
 }