fix: Correctly set t.Date() defaults

src/type-system.ts

@@ -393,21 +393,23 @@ export const ElysiaType = {
 	},
 	Date: (property?: DateOptions) => {
 		const schema = Type.Date(property)
-
+		const _default = property?.default ?
+			new Date(property.default) : // in case the default is an ISO string or milliseconds from epoch
+			undefined;
 		return t
 			.Transform(
 				t.Union(
 					[
 						Type.Date(property),
 						t.String({
 							format: 'date',
-							default: new Date().toISOString()
+							default: _default?.toISOString()
 						}),
 						t.String({
 							format: 'date-time',
-							default: new Date().toISOString()
+							default: _default?.toISOString()
 						}),
-						t.Number()
+						t.Number({ default: _default?.getTime() })
 					],
 					property
 				)

test/type-system/date.test.ts

@@ -1,14 +1,35 @@
 import Elysia, { t } from '../../src'
 import { describe, expect, it } from 'bun:test'
 import { Value } from '@sinclair/typebox/value'
-import { TBoolean, TDate, TypeBoxError } from '@sinclair/typebox'
+import { TBoolean, TDate, TUnion, TypeBoxError } from '@sinclair/typebox'
 import { post } from '../utils'
 
 describe('TypeSystem - Date', () => {
 	it('Create', () => {
 		expect(Value.Create(t.Date())).toBeInstanceOf(Date)
 	})
 
+	it('No default date provided', () => {
+		const schema = t.Date()
+		expect(schema.default).toBeUndefined();
+
+		const unionSchema = schema as unknown as TUnion
+		for (const type of unionSchema.anyOf) {
+			expect(type.default).toBeUndefined();
+		}
+	})
+
+	it('Default date provided', () => {
+		const given = new Date("2025-01-01T00:00:00.000Z")
+		const schema = t.Date({ default: given })
+		expect(schema.default).toEqual(given);
+
+		const unionSchema = schema as unknown as TUnion
+		for (const type of unionSchema.anyOf) {
+			expect(new Date(type.default)).toEqual(given);
+		}
+	})
+
 	it('Check', () => {
 		const schema = t.Date()