Tested
Date Calculator
Add or subtract days, weeks, months, or years from a date.
Date & Calendar Tools
Use CalculatorDate & Calendar Tools
Free date & calendar tools for everyday questions, from quick checks to detailed breakdowns.
Featured calculators
Date & Calendar tools (50)
- Tested
Date Calculator
Add or subtract days, weeks, months, or years from a date.
Date & Calendar Tools
Use Calculator - Tested
Birth Date from Death Date Calculator
Birth date from the date of death and the age at death.
Date & Calendar Tools
Use Calculator - Tested
Birth Year Calculator
Year of birth from a person's age.
Date & Calendar Tools
Use Calculator - Tested
Business Days Calculator
Add or count working days.
Date & Calendar Tools
Use Calculator - Tested
Date of Birth Calculator
Date of birth from an age at a reference date.
Date & Calendar Tools
Use Calculator - Tested
Day of the Week Calculator
Find the weekday of any date.
Date & Calendar Tools
Use Calculator - Tested
Day of the Year Calculator
Which day of the year a date falls on.
Date & Calendar Tools
Use Calculator - Tested
Days Between Dates Calculator
Count days between two dates.
Date & Calendar Tools
Use Calculator - Tested
Days Old Calculator
How many days old you are.
Date & Calendar Tools
Use Calculator - Tested
Days Until Birthday Calculator
Days until your next birthday.
Date & Calendar Tools
Use Calculator - Tested
Days Until Calculator
Days remaining until any date (generalizes “days until June 15”, “days until Christmas” and similar pages).
Date & Calendar Tools
Use Calculator - Tested
Days Until Christmas
Days until Christmas.
Date & Calendar Tools
Use Calculator
All date & calendar tools by topic (49)
Age
Birthdays
Calendars
Date Math
Holidays
- Days Until Christmas
- Days Until Christmas Eve
- Days Until December
- Days Until Easter
- Days Until Father's Day
- Days Until Halloween
- Days Until Inauguration Day
- Days Until International Women's Day
- Days Until Juneteenth
- Days Until Labor Day
- Days Until Leap Day
- Days Until Memorial Day
- Days Until MLK Day
- Days Until Mother's Day
- Days Until New Year's
- Days Until New Year's Eve
- Days Until Presidents' Day
- Days Until St. Patrick's Day
- Days Until Thanksgiving
- Days Until the Fourth of July
- Days Until Valentine's Day
- Days Until Veterans Day
- New Year's Countdown
- Weeks Until Christmas
- Weeks Until Easter
- Weeks Until Halloween
- Weeks Until Thanksgiving
About date & calendar tools
Date & Calendar Tools help you turn a question into a clear, checkable answer. Each tool lists its inputs, shows the formula it relies on and explains how to read the result.
Browse by topic using the filters, or search for a specific tool. Tools that are still being built are clearly marked as previews and are not presented as finished calculators.
Frequently asked questions
Are the date & calendar tools calculators free?
Yes. Every calculator on Calculator Atlas is free to use and requires no sign-up.
How are results verified?
A calculator is only published after its formula has been implemented, tested against reference values and reviewed. Pages still in development are labeled as previews.