diff --git a/src/dayjs.ts b/src/dayjs.ts
new file mode 100644
index 0000000..526f1a2
--- /dev/null
+++ b/src/dayjs.ts
@@ -0,0 +1,10 @@
+import dayjs, {Dayjs} from 'dayjs';
+import duration, {Duration} from 'dayjs/plugin/duration.js';
+import customParseFormat from 'dayjs/plugin/customParseFormat.js';
+
+dayjs.extend(duration);
+dayjs.extend(customParseFormat);
+
+export default dayjs;
+
+export type {Dayjs, Duration};
diff --git a/src/format.ts b/src/format.ts
index a242f7b..b097907 100644
--- a/src/format.ts
+++ b/src/format.ts
@@ -1,4 +1,4 @@
-import dayjs, { Dayjs } from 'dayjs';
+import dayjs, { Dayjs } from './dayjs';
 import { Duration } from 'dayjs/plugin/duration.js';
 import Language from './types/Language';
 import { MessageKey, message } from './i18n';
diff --git a/src/input.ts b/src/input.ts
index 035ed48..afc847d 100644
--- a/src/input.ts
+++ b/src/input.ts
@@ -1,15 +1,12 @@
 import chalk from 'chalk';
-import { Duration } from 'dayjs/plugin/duration';
 import { parseDuration, parseTimestamp } from './parse';
 import * as readline from 'readline/promises';
 import { formatDuration, formatTime } from './format';
-import dayjs, { Dayjs } from 'dayjs';
+import { Dayjs } from 'dayjs';
 import { WtcPromptResult } from './types/WtcPromptResult';
-import duration from 'dayjs/plugin/duration.js';
 import WtcConfig from './types/WtcConfig';
 import { MessageKey, message } from './i18n';
-
-dayjs.extend(duration);
+import dayjs, { Duration } from './dayjs';
 
 const { error } = console;
 
@@ -123,7 +120,7 @@ const input = async (config: WtcConfig): Promise<WtcPromptResult> => {
         const logged = parseDuration(loggedAnswer);
         const unLogged = worked.subtract(logged);
         const workLeft = workDayDuration.subtract(worked);
-        let workLeftMinutes = workLeft.asMinutes();
+        const workLeftMinutes = workLeft.asMinutes();
         let workedOvertime: Duration | undefined;
 
         if (workLeftMinutes < 0) {
diff --git a/src/output.ts b/src/output.ts
index b300000..9d8de7b 100644
--- a/src/output.ts
+++ b/src/output.ts
@@ -3,11 +3,9 @@ import { formatDuration, getHoursRoundedStr } from './format';
 import { WtcPromptResult } from './types/WtcPromptResult';
 import { MessageKey, message } from './i18n.js';
 import WtcConfig from './types/WtcConfig';
-import duration from 'dayjs/plugin/duration.js';
-import dayjs from 'dayjs';
+import dayjs from './dayjs';
 
 const { log } = console;
-dayjs.extend(duration);
 
 const output = (result: WtcPromptResult, config: WtcConfig) => {
     const { language, timestampFormat } = config;
diff --git a/src/parse.ts b/src/parse.ts
index 4abe2fd..7d723fb 100644
--- a/src/parse.ts
+++ b/src/parse.ts
@@ -1,9 +1,4 @@
-import dayjs, { Dayjs } from 'dayjs';
-import customParseFormat from 'dayjs/plugin/customParseFormat.js';
-import duration, { Duration } from 'dayjs/plugin/duration.js';
-
-dayjs.extend(customParseFormat);
-dayjs.extend(duration);
+import dayjs, { Dayjs, Duration } from './dayjs';
 
 export const parseTimestamp = (time: string): Dayjs => (time === 'now' ? dayjs() : dayjs(time, 'HH:mm', true));