diff --git a/components.d.ts b/components.d.ts
index f2c3146f..a70b7f23 100644
--- a/components.d.ts
+++ b/components.d.ts
@@ -65,6 +65,7 @@ declare module '@vue/runtime-core' {
     CTooltip: typeof import('./src/ui/c-tooltip/c-tooltip.vue')['default']
     'CTooltip.demo': typeof import('./src/ui/c-tooltip/c-tooltip.demo.vue')['default']
     DateTimeConverter: typeof import('./src/tools/date-time-converter/date-time-converter.vue')['default']
+    DaysCalculator: typeof import('./src/tools/days-calculator/days-calculator.vue')['default']
     'DemoHome.page': typeof import('./src/ui/demo/demo-home.page.vue')['default']
     DemoWrapper: typeof import('./src/ui/demo/demo-wrapper.vue')['default']
     DeviceInformation: typeof import('./src/tools/device-information/device-information.vue')['default']
@@ -89,6 +90,7 @@ declare module '@vue/runtime-core' {
     HttpStatusCodes: typeof import('./src/tools/http-status-codes/http-status-codes.vue')['default']
     IbanValidatorAndParser: typeof import('./src/tools/iban-validator-and-parser/iban-validator-and-parser.vue')['default']
     'IconMdi:brushVariant': typeof import('~icons/mdi/brush-variant')['default']
+    'IconMdi:contentCopy': typeof import('~icons/mdi/content-copy')['default']
     'IconMdi:kettleSteamOutline': typeof import('~icons/mdi/kettle-steam-outline')['default']
     IconMdiChevronDown: typeof import('~icons/mdi/chevron-down')['default']
     IconMdiChevronRight: typeof import('~icons/mdi/chevron-right')['default']
@@ -126,25 +128,35 @@ declare module '@vue/runtime-core' {
     MenuLayout: typeof import('./src/components/MenuLayout.vue')['default']
     MetaTagGenerator: typeof import('./src/tools/meta-tag-generator/meta-tag-generator.vue')['default']
     MimeTypes: typeof import('./src/tools/mime-types/mime-types.vue')['default']
+    NAlert: typeof import('naive-ui')['NAlert']
     NavbarButtons: typeof import('./src/components/NavbarButtons.vue')['default']
+    NCheckbox: typeof import('naive-ui')['NCheckbox']
     NCode: typeof import('naive-ui')['NCode']
     NCollapseTransition: typeof import('naive-ui')['NCollapseTransition']
     NConfigProvider: typeof import('naive-ui')['NConfigProvider']
+    NDatePicker: typeof import('naive-ui')['NDatePicker']
     NDivider: typeof import('naive-ui')['NDivider']
     NEllipsis: typeof import('naive-ui')['NEllipsis']
+    NForm: typeof import('naive-ui')['NForm']
     NFormItem: typeof import('naive-ui')['NFormItem']
     NGi: typeof import('naive-ui')['NGi']
     NGrid: typeof import('naive-ui')['NGrid']
     NH1: typeof import('naive-ui')['NH1']
     NH3: typeof import('naive-ui')['NH3']
     NIcon: typeof import('naive-ui')['NIcon']
+    NInputGroup: typeof import('naive-ui')['NInputGroup']
+    NInputGroupLabel: typeof import('naive-ui')['NInputGroupLabel']
     NInputNumber: typeof import('naive-ui')['NInputNumber']
     NLabel: typeof import('naive-ui')['NLabel']
     NLayout: typeof import('naive-ui')['NLayout']
     NLayoutSider: typeof import('naive-ui')['NLayoutSider']
     NMenu: typeof import('naive-ui')['NMenu']
     NScrollbar: typeof import('naive-ui')['NScrollbar']
+    NSlider: typeof import('naive-ui')['NSlider']
     NSpin: typeof import('naive-ui')['NSpin']
+    NStatistic: typeof import('naive-ui')['NStatistic']
+    NSwitch: typeof import('naive-ui')['NSwitch']
+    NTable: typeof import('naive-ui')['NTable']
     NumeronymGenerator: typeof import('./src/tools/numeronym-generator/numeronym-generator.vue')['default']
     OtpCodeGeneratorAndValidator: typeof import('./src/tools/otp-code-generator-and-validator/otp-code-generator-and-validator.vue')['default']
     PasswordStrengthAnalyser: typeof import('./src/tools/password-strength-analyser/password-strength-analyser.vue')['default']
diff --git a/locales/en.yml b/locales/en.yml
index d09d435a..3f1d3b06 100644
--- a/locales/en.yml
+++ b/locales/en.yml
@@ -92,6 +92,11 @@ tools:
     button:
       copy: Copy
       refresh: Refresh
+      
+  days-calculator:
+    title: Days calculator
+    description: Find the number of days between two dates.
+
   percentage-calculator:
     title: Percentage calculator
     description: Easily calculate percentages from a value to another value, or from a percentage to a value.
diff --git a/locales/zh.yml b/locales/zh.yml
index 160fe1fa..221defb1 100644
--- a/locales/zh.yml
+++ b/locales/zh.yml
@@ -91,6 +91,11 @@ tools:
     button:
       copy: 复制
       refresh: 刷新
+
+  days-calculator:
+    title: 天数计算器
+    description: 计算两个日期之间的天数。
+
   percentage-calculator:
     title: 百分比计算器
     description: 轻松计算从一个值到另一个值的百分比，或从百分比到值的百分比。
diff --git a/src/tools/days-calculator/days-calculator.service.ts b/src/tools/days-calculator/days-calculator.service.ts
new file mode 100644
index 00000000..6c061a9d
--- /dev/null
+++ b/src/tools/days-calculator/days-calculator.service.ts
@@ -0,0 +1,16 @@
+import { formatDuration } from 'date-fns';
+
+export function formatMsDuration(duration: number) {
+  const ms = Math.floor(duration % 1000);
+  const secs = Math.floor(((duration - ms) / 1000) % 60);
+  const mins = Math.floor((((duration - ms) / 1000 - secs) / 60) % 60);
+  const hrs = Math.floor((((duration - ms) / 1000 - secs) / 60 - mins) / 60);
+
+  return (
+    formatDuration({
+      hours: hrs,
+      minutes: mins,
+      seconds: secs,
+    }) + (ms > 0 ? ` ${ms} ms` : '')
+  );
+}
diff --git a/src/tools/days-calculator/days-calculator.vue b/src/tools/days-calculator/days-calculator.vue
new file mode 100644
index 00000000..534b2e2e
--- /dev/null
+++ b/src/tools/days-calculator/days-calculator.vue
@@ -0,0 +1,37 @@
+<script setup lang="ts">
+const startDate = ref<Date | null>(null);
+const endDate = ref<Date | null>(null);
+const includeEndDate = ref(false);
+
+const calculatedDays = computed<string | null>(() => {
+  if (startDate.value && endDate.value) {
+    const start = new Date(startDate.value);
+    const end = new Date(endDate.value);
+    if (!Number.isNaN(start.getTime()) && !Number.isNaN(end.getTime())) {
+      const diff = Math.abs(end.getTime() - start.getTime());
+      const days = Math.ceil(diff / (1000 * 60 * 60 * 24));
+      return (includeEndDate.value ? days + 1 : days).toString();
+    }
+  }
+  return null;
+});
+</script>
+
+<template>
+  <div>
+    <n-form>
+      <div w-full flex gap-4>
+        <n-form-item label="Start Date">
+          <n-date-picker v-model:value="startDate" type="date" />
+        </n-form-item>
+        <n-form-item label="End Date">
+          <n-date-picker v-model:value="endDate" type="date" />
+        </n-form-item>
+      </div>
+      <n-form-item label="Include end date in calculation (1 day is added)" label-placement="left">
+        <n-checkbox v-model:checked="includeEndDate" />
+      </n-form-item>
+    </n-form>
+    <c-input-text label="Calculated days" :value="calculatedDays" readonly />
+  </div>
+</template>
diff --git a/src/tools/days-calculator/index.ts b/src/tools/days-calculator/index.ts
new file mode 100644
index 00000000..458ec819
--- /dev/null
+++ b/src/tools/days-calculator/index.ts
@@ -0,0 +1,12 @@
+import { CalendarPlus } from '@vicons/tabler';
+import { defineTool } from '../tool';
+import { translate } from '@/plugins/i18n.plugin';
+
+export const tool = defineTool({
+  name: translate('tools.days-calculator.title'),
+  path: '/days-calculator',
+  description: translate('tools.days-calculator.description'),
+  keywords: ['days', 'calculator', 'between', 'two', 'dates'],
+  component: () => import('./days-calculator.vue'),
+  icon: CalendarPlus,
+});
diff --git a/src/tools/index.ts b/src/tools/index.ts
index aa861c93..f3f47bb2 100644
--- a/src/tools/index.ts
+++ b/src/tools/index.ts
@@ -52,6 +52,7 @@ import { tool as dateTimeConverter } from './date-time-converter';
 import { tool as deviceInformation } from './device-information';
 import { tool as cypher } from './encryption';
 import { tool as etaCalculator } from './eta-calculator';
+import { tool as daysCalculator } from './days-calculator';
 import { tool as percentageCalculator } from './percentage-calculator';
 import { tool as gitMemo } from './git-memo';
 import { tool as hashText } from './hash-text';
@@ -156,7 +157,7 @@ export const toolsByCategory: ToolCategory[] = [
   },
   {
     name: 'Math',
-    components: [mathEvaluator, etaCalculator, percentageCalculator],
+    components: [mathEvaluator, etaCalculator, percentageCalculator, daysCalculator],
   },
   {
     name: 'Measurement',