diff --git a/lib/index.ts b/lib/index.ts
index c312207..ff9b698 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -1,29 +1,27 @@
-import * as moment from 'moment';
-import Diff = moment.unitOfTime.Diff;
-import DurationConstructor = moment.unitOfTime.DurationConstructor;
-import { Options } from './types';
-import { ReturnObj } from './types';
+import { Options, Units } from './types';
+import * as dayjs from 'dayjs';
+import { ManipulateType, UnitTypeLongPlural } from 'dayjs';
 
 function timediff<ReturnZeros extends boolean = false>(
   start: Date | string | 'now',
   end: Date | string | 'now',
   options?: Options<ReturnZeros>,
-): ReturnZeros extends true ? ReturnObj : Partial<ReturnObj> {
+): ReturnZeros extends true ? Units : Partial<Units> {
   const now = new Date();
 
-  const sd = moment(start === 'now' ? now : start);
+  let sd = dayjs(start === 'now' ? now : start);
   if (!sd.isValid()) {
     throw 'invalid start date ' + sd;
   }
-  const ed = moment(end === 'now' ? now : end);
+  const ed = dayjs(end === 'now' ? now : end);
   if (!ed.isValid()) {
     throw 'invalid end date ' + ed;
   }
 
   const config: {
-    units: Record<keyof ReturnObj, boolean>;
+    units: Record<keyof Units, boolean>;
     returnZeros: boolean;
-    callback: ((result: ReturnObj | Partial<ReturnObj>) => unknown) | undefined;
+    callback: ((result: Units | Partial<Units>) => unknown) | undefined;
   } = {
     units: {
       years: true,
@@ -101,18 +99,18 @@ function timediff<ReturnZeros extends boolean = false>(
     }
   }
 
-  const result: Partial<ReturnObj> = {};
+  const result: Partial<Units> = {};
   for (let unit in config.units) {
-    if (config.units[unit as keyof ReturnObj]) {
-      const value = ed.diff(sd, unit as Diff);
-      sd.add(value, unit as DurationConstructor);
+    if (config.units[unit as keyof Units]) {
+      const value = ed.diff(sd, unit as UnitTypeLongPlural);
+      sd = sd.add(value, unit as ManipulateType);
       if (config.returnZeros || value != 0) {
-        result[unit as keyof ReturnObj] = value;
+        result[unit as keyof Units] = value;
       }
     }
   }
 
-  return result as ReturnZeros extends true ? ReturnObj : Partial<ReturnObj>;
+  return result as ReturnZeros extends true ? Units : Partial<Units>;
 }
 
-export { timediff, ReturnObj, Options }
+export { timediff, Units, Options }
diff --git a/lib/types.ts b/lib/types.ts
index 8800005..5b804bc 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -1,4 +1,4 @@
-export interface ReturnObj {
+export interface Units {
   years: number;
   months: number;
   weeks: number;
@@ -10,7 +10,7 @@ export interface ReturnObj {
 }
 
 export interface OptionsObj<ReturnZeros extends boolean> {
-  units?: string | Partial<Record<keyof ReturnObj, boolean>>;
+  units?: string | Partial<Record<keyof Units, boolean>>;
   returnZeros?: ReturnZeros;
 }
 
diff --git a/package-lock.json b/package-lock.json
index b94d12c..67117bc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,19 +1,18 @@
 {
   "name": "@marc-maniac/timediff",
-  "version": "0.3.8",
+  "version": "0.4.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@marc-maniac/timediff",
-      "version": "0.3.8",
+      "version": "0.4.0",
       "license": "MIT",
       "dependencies": {
+        "date-fns": "^3.6.0",
+        "dayjs": "^1.11.11",
         "moment": "^2.9.0"
       },
-      "bin": {
-        "timediff": "cli.js"
-      },
       "devDependencies": {
         "@types/mocha": "^10.0.6",
         "expect": "^29.7.0",
@@ -500,6 +499,20 @@
       "integrity": "sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==",
       "dev": true
     },
+    "node_modules/date-fns": {
+      "version": "3.6.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-3.6.0.tgz",
+      "integrity": "sha512-fRHTG8g/Gif+kSh50gaGEdToemgfj74aRX3swtiouboip5JDLAyDE9F11nHMIcvOaXeOC6D7SpNhi7uFyB7Uww==",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/kossnocorp"
+      }
+    },
+    "node_modules/dayjs": {
+      "version": "1.11.11",
+      "resolved": "https://registry.npmjs.org/dayjs/-/dayjs-1.11.11.tgz",
+      "integrity": "sha512-okzr3f11N6WuqYtZSvm+F776mB41wRZMhKP+hc34YdW+KmtYYK9iqvHSwo2k9FEH3fhGXvOPV6yz2IcSrfRUDg=="
+    },
     "node_modules/debug": {
       "version": "4.3.4",
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
diff --git a/package.json b/package.json
index a5bc2a4..561c44d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@marc-maniac/timediff",
-  "version": "0.3.8",
+  "version": "0.4.0",
   "description": "Calculate a time difference in several time units.",
   "license": "MIT",
   "main": "dist/index.js",
@@ -30,7 +30,7 @@
     "url": "git+https://github.com/marc-at-brightnight/timediff.git"
   },
   "dependencies": {
-    "moment": "^2.9.0"
+    "dayjs": "^1.11.11"
   },
   "devDependencies": {
     "@types/mocha": "^10.0.6",
diff --git a/test/index.spec.ts b/test/index.spec.ts
index 6fe59d3..5dc98ba 100644
--- a/test/index.spec.ts
+++ b/test/index.spec.ts
@@ -1,4 +1,4 @@
-import * as moment from 'moment';
+import * as dayjs from "dayjs";
 import { timediff } from '../lib';
 import expect from 'expect';
 import { Options } from '../lib';
@@ -27,7 +27,7 @@ describe('timediff', function () {
     }).not.toThrow();
     expect(function () {
       // @ts-ignore
-      timediff(new Date(), moment());
+      timediff(new Date(), dayjs());
     }).not.toThrow();
   });