Days Until Calculator

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days until calculator
Total Days RemainingBusiness Days Only (Mon-Fri)Weeks and Days
Result:
Time Remaining: —
var today = new Date().toISOString().split('T')[0];document.getElementById('startDate').value = today;function calculateDays(){var startVal = document.getElementById('startDate').value;var targetVal = document.getElementById('targetDate').value;var mode = document.getElementById('calc_type').value;var inclusive = document.getElementById('inclusive').checked;if(!startVal || !targetVal){alert('Please select both start and target dates.');return;}var start = new Date(startVal);var target = new Date(targetVal);if(target < start){document.getElementById('resultValue').innerHTML = "Target date is in the past";document.getElementById('stepDetails').innerHTML = "";return;}var diffTime = Math.abs(target – start);var diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));if(inclusive){diffDays += 1;}if(mode === "total"){document.getElementById('resultValue').innerHTML = diffDays + " Days";document.getElementById('stepDetails').innerHTML = "Total calendar days between dates.";}else if(mode === "business"){var count = 0;var curDate = new Date(start);while(curDate 0){count = count;} // Logic handled by while loopdocument.getElementById('resultValue').innerHTML = count + " Working Days";document.getElementById('stepDetails').innerHTML = "Excluding Saturdays and Sundays.";}else if(mode === "weeks"){var weeks = Math.floor(diffDays / 7);var remainingDays = diffDays % 7;document.getElementById('resultValue').innerHTML = weeks + " Weeks, " + remainingDays + " Days";document.getElementById('stepDetails').innerHTML = "Broken down into full weeks.";}}

Calculator Use

The days until calculator is a precise tool designed to help you track the exact amount of time remaining until a specific event, deadline, or milestone. Whether you are counting down to a wedding, a project deadline, or a long-awaited vacation, this tool provides instant accuracy for planning purposes.

By default, the calculator uses today's date as the starting point, but you can manually adjust the start date to plan for future intervals. You can choose between total calendar days, business days, or a week-by-week breakdown to suit your specific scheduling needs.

Start Date
The beginning of your countdown. Usually set to "today" to find out how much time is left from right now.
Target Date
The specific calendar date of the event you are waiting for.
Calculation Mode
Choose between "Total Days" (all days), "Business Days" (Monday through Friday), or "Weeks and Days" for a high-level view.

How It Works

When calculating the duration between two points in time, the days until calculator uses a standardized mathematical approach based on the Unix epoch time. The formula for the simplest calculation is:

Total Days = (Target Date Timestamp – Start Date Timestamp) / 86,400,000

  • Timestamp: The number of milliseconds elapsed since January 1, 1970.
  • 86,400,000: The number of milliseconds in a single 24-hour day (24 hours × 60 minutes × 60 seconds × 1000 ms).
  • Inclusivity: By default, most date math excludes the end date. If you check "Include End Date," the formula adds 1 to the final result to count the target day itself as a full day of progress.

Calculation Example

Example: Suppose today is October 1st and you have a major project due on October 15th. You want to know the total days and business days remaining.

Step-by-step solution:

  1. Start Date = October 1
  2. Target Date = October 15
  3. Total Days Calculation: 15 – 1 = 14 calendar days.
  4. Business Days Calculation: We exclude the two weekends (Saturdays and Sundays) falling within that window. If there are 4 weekend days, the result is 10 business days.
  5. Final Result: 14 Total Days / 10 Working Days.

Common Questions

Does this calculator account for leap years?

Yes. Because the tool uses the underlying JavaScript Date object, it automatically accounts for the extra day in February during leap years (2024, 2028, etc.). Your countdown will remain accurate regardless of the year.

What is the difference between "Inclusive" and "Exclusive" dates?

Exclusive calculation (default) tells you how many full 24-hour periods exist between now and the event. Inclusive calculation assumes the final day is also a day you are "working" or "waiting," effectively adding 1 to the total count. This is common in legal contracts or rental agreements.

Can I calculate business days only?

Yes, simply select "Business Days Only" from the dropdown menu. This will strip out all Saturdays and Sundays from the total count, giving you a better idea of how many workdays are left before a deadline. Note that this specific tool does not automatically subtract regional bank holidays, as these vary by country.

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