Our date calculators are highly accurate and follow standard calendar rules. They account for leap years, different month lengths, and time zone considerations where applicable. All calculations are performed using JavaScript's built-in Date object, which follows the Gregorian calendar system. We implement additional validation and error checking to ensure results are precise down to the day, accounting for edge cases like century leap year rules (years divisible by 100 are not leap years unless divisible by 400), month boundary transitions, and year transitions. For critical calculations, we recommend verifying results, especially for legal or medical purposes where absolute precision is required.

Yes, our calculators are completely free to use for both personal and business purposes. They are particularly useful for project planning, deadline calculations, business day counting, employee age calculations, contract period tracking, and any scenario requiring accurate date computations. No registration, payment, or subscription is required - now or ever. We believe essential calculation tools should be accessible to everyone. Whether you're a student, professional, business owner, or individual planning personal events, you can use our calculators without any limitations or hidden costs.

Most of our calculators support dates from 1900 to 2100, which covers the vast majority of practical use cases including historical research, current planning, and future projections. This range accounts for the complete 20th and 21st centuries, plus the beginning of the 22nd century. Some calculators may have different ranges based on their specific functionality. For example, the leap year calculator can check any year, while business day calculators work best with current and near-future dates. If you need calculations outside these ranges, please contact us - we're always working to expand our capabilities based on user needs.

Yes, all our calculators are fully responsive and work perfectly on mobile devices, tablets, and desktop computers. The interface automatically adapts to different screen sizes for optimal user experience.

Our Business Days Calculator automatically excludes weekends (Saturday and Sunday) from the calculation. Simply enter your start and end dates, and it will calculate the number of working days between them. Note that holidays are not automatically excluded and would need to be manually subtracted if required.

Days between dates counts all calendar days including weekends, while business days only counts weekdays (Monday through Friday). Business days are commonly used for project planning and deadline calculations in professional settings.

Our leap year calculator follows the standard Gregorian calendar rules: a year is a leap year if it's divisible by 4, except for years divisible by 100. However, years divisible by 400 are still leap years. This means 2000 was a leap year, but 1900 and 2100 are not.

Yes, our Age Calculator provides age in years, months, and days, as well as the total number of days lived. This gives you a comprehensive view of someone's age in multiple formats for different purposes.

Our pregnancy calculator provides an estimated due date based on the last menstrual period (LMP) method, which is the standard method used by healthcare providers. However, actual due dates can vary, and this should be used as a general guide. Always consult with a healthcare provider for medical advice.

No, we do not store any personal data, calculation results, dates you enter, or any information about your usage. All calculations are performed entirely locally in your browser using JavaScript - your data never leaves your device. We don't use cookies to track your activity, we don't require registration, and we don't collect analytics that could identify you. This ensures complete privacy and security for your calculations, making our tools safe for sensitive information like medical dates, legal deadlines, or personal milestones. Your privacy is fundamental to our mission - we provide powerful tools without compromising your personal information.

Yes, all our calculators are completely free to use with no hidden costs, registration requirements, or usage limits. We believe in providing accessible tools for everyone to use for their date and time calculation needs.

Yes, once the page is loaded, you can use most calculators offline. However, some features like time zone calculations may require an internet connection for accurate time zone data. We recommend using the calculators online for the best experience.

We welcome feedback! If you encounter any issues or have suggestions for new features, please contact us through our contact page. We regularly update our calculators based on user feedback to improve functionality and user experience.