Days Counter Tool

Calculate days between two dates instantly. Shows business days, weeks, years/months/days, and Japanese era display. Real-time results with no button clicks needed.

Last updated: 2026/03/01 Calculator
0 days
Weeks + Days
-
Years / Months / Days
-
Business Days
-
Weekends & Holidays
-
Start Date -
End Date -
Business Day Details (Excluded Holidays)

How to Use

1

Enter Start and End Dates

Enter the start and end dates using the date inputs. Click "Today" for quick input. The start date defaults to today.

2

View Real-time Results

Results update instantly as you type. View days, weeks + days, years/months/days, business days (excluding weekends & holidays), and Japanese era at a glance.

3

Copy and Share Results

Click "Copy Result" to copy the calculation results to your clipboard in text format. Share via email, chat, or social media.

About Days Counter

A web tool that instantly calculates the number of days between two dates. Features business day counting (excluding weekends and Japanese holidays), weeks + days conversion, years/months/days breakdown, and Japanese era display. All processing happens in your browser - no data is sent to any server.

Features

  • Real-time CalculationResults appear instantly as you enter dates. No button clicks needed - days, weeks, years, and business days update immediately.
  • Business Day CountingAutomatically excludes weekends and 16 Japanese national holidays. View the list of excluded holidays in detail.
  • Multiple Unit DisplayView results in days, weeks + days, and years + months + days. Choose the format that suits your needs.
  • Japanese Era SupportAutomatically displays the Japanese era (Reiwa, Heisei, Showa, etc.) for both start and end dates.

Use Cases

  • Count days since you started dating or got married
  • Calculate days since joining or leaving a company
  • Track project elapsed days
  • Count days since a baby was born
  • Calculate remaining contract days and business days

FAQ

What does "Include start date" mean?
It determines whether to count the start date as day 1. For example, Jan 1 to Jan 3: excluding start = 2 days, including start = 3 days. For "how many days since" type questions, including the start date is usually appropriate.
How are business days calculated?
Saturdays, Sundays, and 16 Japanese national holidays (New Year's Day, Coming of Age Day, etc.) plus substitute holidays are excluded. Equinox dates are calculated astronomically.
What if the start date is after the end date?
The dates are automatically swapped for calculation, and a note is displayed. You can use the "Swap" button to correct the order.
How is this different from the Date Calculator?
The Date Calculator is a multi-mode tool with duration, add/subtract, and business day calculations. This tool focuses specifically on counting days between dates for a simpler, more intuitive experience.
How is the Japanese era displayed?
The corresponding era (Reiwa, Heisei, Showa, Taisho, Meiji) is automatically shown for both start and end dates.
Can I share results via URL?
Yes, you can share a URL with parameters (e.g., ?start=2025-01-01&end=2026-03-01) to let others see the same calculation.
Is my data saved?
No, all processing is done entirely in your browser. No data is sent to or stored on any server.
Can I use this on my smartphone?
Yes, the tool is fully responsive and works on smartphones, tablets, and desktops. Native date pickers are used on mobile devices.
Can I copy the results?
Yes, click "Copy Result" to copy days, weeks, years/months/days, and business days to your clipboard in text format.
How far ahead does the holiday data cover?
The astronomical equinox formulas cover up to 2099. Happy Monday holidays and fixed holidays are also calculated automatically.