Day Counter

Calculate the number of days between two dates or count days from a specific date. Include business days, weekends, and holidays in your calculations with our comprehensive day counter.

days

Calculation Results

How to Use the Day Counter

Our day counter offers two powerful calculation modes to help you work with dates effectively:

Days Between Dates

Select a start date and end date to calculate the exact number of days between them. You can choose to include or exclude the end day in your calculation. The calculator provides a detailed breakdown showing total days, weekdays, weekends, and any holidays that fall within your selected date range.

Count Days from a Date

Start with a specific date and add or subtract a number of days to find the resulting date. This is perfect for calculating project deadlines, future appointments, or determining dates a certain number of days in the past. Enable "business days only" to exclude weekends from your calculation.

Holiday and Business Day Settings

Customize your calculations by including or excluding holidays. Our calculator includes all major US federal holidays and allows you to add custom holidays specific to your needs. Business day calculations automatically exclude weekends and can also exclude holidays for accurate project planning.

Understanding Day of the Week Calculations

The calculator shows the day of the week for your selected dates using proven algorithms. This feature is particularly useful for planning events, scheduling meetings, or determining which day of the week a particular date falls on.

The Doomsday Algorithm

Named after mathematician John Conway, the Doomsday rule is a method for determining the day of the week for any date. The algorithm is based on "doomsdays" - specific dates that all fall on the same day of the week in any given year. These reference points make it possible to calculate the day of the week for any date with simple arithmetic.

Key Doomsday Dates

Some memorable doomsday dates include 4/4, 6/6, 8/8, 10/10, and 12/12 (all even months except February). For odd months, remember "I work from 9 to 5 at 7-Eleven" which gives you 9/5, 5/9, 7/11, and 11/7. January's doomsday is 1/3 (or 1/4 in leap years), while February's is the last day of the month.

Practical Applications

Project Management: Calculate business days for project timelines
Event Planning: Determine dates for recurring events or celebrations
Financial Calculations: Calculate interest periods or payment due dates
Personal Planning: Count down to birthdays, anniversaries, or vacations
Academic Scheduling: Plan semester dates, assignment due dates, and exam periods
Legal Deadlines: Calculate filing deadlines and statute of limitations dates

Whether you're planning a project, organizing an event, or simply curious about dates, our day counter provides accurate calculations with the flexibility to accommodate your specific needs and regional holidays.