diff --git a/ts/packages/agents/calendar/jest.config.cjs b/ts/packages/agents/calendar/jest.config.cjs
new file mode 100644
index 000000000..f475768a1
--- /dev/null
+++ b/ts/packages/agents/calendar/jest.config.cjs
@@ -0,0 +1,4 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+module.exports = require("../../../jest.config.js");
diff --git a/ts/packages/agents/calendar/package.json b/ts/packages/agents/calendar/package.json
index 407fc6fbf..9c1bac775 100644
--- a/ts/packages/agents/calendar/package.json
+++ b/ts/packages/agents/calendar/package.json
@@ -21,9 +21,12 @@
     "asc": "asc -i ./src/calendarActionsSchemaV3.ts -o ./dist/calendarSchema.pas.json -t CalendarActionV3 -e CalendarEntities",
     "build": "concurrently npm:tsc npm:asc npm:agc",
     "clean": "rimraf --glob dist *.tsbuildinfo *.done.build.log",
+    "jest-esm": "node --no-warnings --experimental-vm-modules ./node_modules/jest/bin/jest.js",
     "prettier": "prettier --check . --ignore-path ../../../.prettierignore",
     "prettier:fix": "prettier --write . --ignore-path ../../../.prettierignore",
-    "tsc": "tsc -b"
+    "test": "npm run test:local",
+    "test:local": "pnpm run jest-esm --testPathPattern=\".*[.]spec[.]js\"",
+    "tsc": "tsc -b src test"
   },
   "dependencies": {
     "@typeagent/agent-sdk": "workspace:*",
@@ -36,8 +39,10 @@
   "devDependencies": {
     "@typeagent/action-schema-compiler": "workspace:*",
     "@types/debug": "^4.1.12",
+    "@types/jest": "^29.5.7",
     "action-grammar-compiler": "workspace:*",
     "concurrently": "^9.1.2",
+    "jest": "^29.7.0",
     "prettier": "^3.5.3",
     "rimraf": "^6.0.1",
     "typescript": "~5.4.5"
diff --git a/ts/packages/agents/calendar/src/calendarActionHandlerV3.ts b/ts/packages/agents/calendar/src/calendarActionHandlerV3.ts
index b7a365e2b..1909ac298 100644
--- a/ts/packages/agents/calendar/src/calendarActionHandlerV3.ts
+++ b/ts/packages/agents/calendar/src/calendarActionHandlerV3.ts
@@ -1117,15 +1117,37 @@ export function instantiate(): AppAgent {
 // These will be called by the grammar matcher to validate wildcard matches
 
 export function validateCalendarDate(value: string): boolean {
-    // TODO: Implement sophisticated date parsing
-    // For now, accept any non-empty string
-    return value.trim().length > 0;
+    const trimmed = value.trim();
+    if (trimmed.length === 0) return false;
+    if (/^(today|tomorrow|yesterday)$/i.test(trimmed)) return true;
+    if (/^(next|last|this)\s+\w+$/i.test(trimmed)) return true;
+    return parseFuzzyDateString(trimmed) !== undefined;
 }
 
 export function validateCalendarTime(value: string): boolean {
-    // TODO: Implement sophisticated time parsing
-    // For now, accept any non-empty string
-    return value.trim().length > 0;
+    const trimmed = value.trim();
+    if (trimmed.length === 0) return false;
+    if (/^(noon|midnight|morning|evening|afternoon|night)$/i.test(trimmed))
+        return true;
+    if (/^\d{1,2}:\d{2}$/.test(trimmed)) {
+        const [h, m] = trimmed.split(":").map(Number);
+        return h >= 0 && h <= 23 && m >= 0 && m <= 59;
+    }
+    if (/^\d{1,2}(am|pm)$/i.test(trimmed)) {
+        const h = parseInt(trimmed, 10);
+        return h >= 1 && h <= 12;
+    }
+    if (/^\d{1,2}:\d{2}(am|pm)$/i.test(trimmed)) {
+        const [timePart] = trimmed.split(/[ap]m/i);
+        const [h, m] = timePart.split(":").map(Number);
+        return h >= 1 && h <= 12 && m >= 0 && m <= 59;
+    }
+    try {
+        parseTimeString(trimmed);
+        return true;
+    } catch {
+        return false;
+    }
 }
 
 export function validateEventDescription(value: string): boolean {
diff --git a/ts/packages/agents/calendar/test/calendarValidation.spec.ts b/ts/packages/agents/calendar/test/calendarValidation.spec.ts
new file mode 100644
index 000000000..a9089cc64
--- /dev/null
+++ b/ts/packages/agents/calendar/test/calendarValidation.spec.ts
@@ -0,0 +1,75 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+import {
+    validateCalendarDate,
+    validateCalendarTime,
+} from "../src/calendarActionHandlerV3.js";
+
+describe("validateCalendarDate", () => {
+    test("rejects empty string", () => {
+        expect(validateCalendarDate("")).toBe(false);
+        expect(validateCalendarDate("   ")).toBe(false);
+    });
+
+    test("accepts today/tomorrow/yesterday", () => {
+        expect(validateCalendarDate("today")).toBe(true);
+        expect(validateCalendarDate("Tomorrow")).toBe(true);
+        expect(validateCalendarDate("YESTERDAY")).toBe(true);
+    });
+
+    test("accepts relative terms (next/last/this)", () => {
+        expect(validateCalendarDate("next Monday")).toBe(true);
+        expect(validateCalendarDate("last Friday")).toBe(true);
+        expect(validateCalendarDate("this week")).toBe(true);
+    });
+
+    test("accepts parseable date strings", () => {
+        expect(validateCalendarDate("March 15, 2025")).toBe(true);
+        expect(validateCalendarDate("2025-03-15")).toBe(true);
+    });
+
+    test("rejects nonsense strings", () => {
+        expect(validateCalendarDate("xyzzy")).toBe(false);
+        expect(validateCalendarDate("notadate")).toBe(false);
+    });
+});
+
+describe("validateCalendarTime", () => {
+    test("rejects empty string", () => {
+        expect(validateCalendarTime("")).toBe(false);
+        expect(validateCalendarTime("   ")).toBe(false);
+    });
+
+    test("accepts named times", () => {
+        expect(validateCalendarTime("noon")).toBe(true);
+        expect(validateCalendarTime("midnight")).toBe(true);
+        expect(validateCalendarTime("morning")).toBe(true);
+        expect(validateCalendarTime("evening")).toBe(true);
+        expect(validateCalendarTime("afternoon")).toBe(true);
+        expect(validateCalendarTime("night")).toBe(true);
+    });
+
+    test("accepts HH:MM 24-hour format", () => {
+        expect(validateCalendarTime("9:00")).toBe(true);
+        expect(validateCalendarTime("14:30")).toBe(true);
+        expect(validateCalendarTime("23:59")).toBe(true);
+        expect(validateCalendarTime("0:00")).toBe(true);
+    });
+
+    test("rejects invalid HH:MM values", () => {
+        expect(validateCalendarTime("25:00")).toBe(false);
+        expect(validateCalendarTime("12:60")).toBe(false);
+    });
+
+    test("accepts 12-hour format strings", () => {
+        expect(validateCalendarTime("3pm")).toBe(true);
+        expect(validateCalendarTime("10am")).toBe(true);
+        expect(validateCalendarTime("3:30pm")).toBe(true);
+    });
+
+    test("rejects nonsense strings", () => {
+        expect(validateCalendarTime("xyzzy")).toBe(false);
+        expect(validateCalendarTime("notatime")).toBe(false);
+    });
+});
diff --git a/ts/packages/agents/calendar/test/tsconfig.json b/ts/packages/agents/calendar/test/tsconfig.json
new file mode 100644
index 000000000..895a6f0d2
--- /dev/null
+++ b/ts/packages/agents/calendar/test/tsconfig.json
@@ -0,0 +1,14 @@
+{
+  "extends": "../../../../tsconfig.base.json",
+  "compilerOptions": {
+    "composite": true,
+    "rootDir": ".",
+    "outDir": "../dist/test",
+    "types": ["node", "jest"]
+  },
+  "include": ["./**/*"],
+  "ts-node": {
+    "esm": true
+  },
+  "references": [{ "path": "../src" }]
+}
diff --git a/ts/packages/agents/calendar/tsconfig.json b/ts/packages/agents/calendar/tsconfig.json
index acb9cb4a9..94dfc60bb 100644
--- a/ts/packages/agents/calendar/tsconfig.json
+++ b/ts/packages/agents/calendar/tsconfig.json
@@ -4,7 +4,7 @@
     "composite": true
   },
   "include": [],
-  "references": [{ "path": "./src" }],
+  "references": [{ "path": "./src" }, { "path": "./test" }],
   "ts-node": {
     "esm": true
   }
diff --git a/ts/pnpm-lock.yaml b/ts/pnpm-lock.yaml
index e412949ef..e19a6b5b8 100644
--- a/ts/pnpm-lock.yaml
+++ b/ts/pnpm-lock.yaml
@@ -1609,12 +1609,18 @@ importers:
       '@types/debug':
         specifier: ^4.1.12
         version: 4.1.12
+      '@types/jest':
+        specifier: ^29.5.7
+        version: 29.5.14
       action-grammar-compiler:
         specifier: workspace:*
         version: link:../../actionGrammarCompiler
       concurrently:
         specifier: ^9.1.2
         version: 9.1.2
+      jest:
+        specifier: ^29.7.0
+        version: 29.7.0(@types/node@25.5.2)(ts-node@10.9.2(@types/node@25.5.2)(typescript@5.4.5))
       prettier:
         specifier: ^3.5.3
         version: 3.5.3