diff --git a/packages/koishi-utils/src/date.ts b/packages/koishi-utils/src/date.ts
index 21077075e4..8131415c28 100644
--- a/packages/koishi-utils/src/date.ts
+++ b/packages/koishi-utils/src/date.ts
@@ -1,4 +1,5 @@
-export function getDateNumber (date = new Date()) {
+export function getDateNumber (date: number | Date = new Date()) {
+  if (typeof date === 'number') date = new Date(date)
   return Math.floor(Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()) / 86400000)
 }
 
diff --git a/packages/koishi-utils/tests/date.spec.ts b/packages/koishi-utils/tests/date.spec.ts
index d4d522d825..0df05f29cb 100644
--- a/packages/koishi-utils/tests/date.spec.ts
+++ b/packages/koishi-utils/tests/date.spec.ts
@@ -4,6 +4,7 @@ describe('Date Manipulations', () => {
   test('getDateNumber', () => {
     getDateNumber() /* make coverage happy */
     expect(getDateNumber(new Date(2020, 0))).toBe(18262)
+    expect(getDateNumber(1577808000000)).toBe(18262)
   })
 
   test('fromDateNumber', () => {