Calculate days between dates, add or subtract days, or count business days accurately with LiteCalc’s Date Calculator. Whether you’re scheduling events, managing deadlines, or planning projects, this tool makes time tracking simple and precise.
Between the selected dates
Use the first tab to count the gap between a start date and end date. Use the second tab to add or subtract years, months, weeks, or days from one base date. Turn on the business-days option when weekends should not count.
Pick the date range tool for elapsed time or the add/subtract tool for future and past dates.
Select your start date, end date, or base date from the built-in picker so the format stays correct.
Choose calendar days for full date spans or business days when only weekdays matter.
Check whether you need inclusive counting before you use the result for a notice, booking, or event.
Calendar days count every day on the calendar, including weekends. Business days usually count Monday through Friday only. That difference matters when you are planning delivery windows, payroll timing, office deadlines, and service turnaround times.
If you compare January 15, 2026 to April 15, 2026, the calendar span is 90 days. A weekday-only result will be lower because Saturdays and Sundays are removed. This is why a five-business-day promise often stretches across a longer calendar span.
The add/subtract tool answers a different question. Instead of measuring the gap between two dates, it tells you the destination date after moving a base date forward or backward.
Month length, leap year rules, and whether you count the end date can all change your final answer. February can have 28 or 29 days. Some months have 30 days while others have 31. The calculator handles these differences automatically inside the Gregorian calendar.
If a result feels off, the problem is usually not the math. It is the rule. Ask whether you need calendar days, business days, or inclusive counting, then use the answer that matches the real-world process.
The core date-difference formula is: Days = End Date − Start Date. Internally, each date is stored as a serial number — the count of days since a reference point. The calculator subtracts the start serial number from the end serial number. If you need inclusive counting, add 1 to the result.
For the business-day count, the formula iterates through each day in the range and increments a counter only when the day falls Monday through Friday, skipping Saturday and Sunday. For adding or subtracting time, the calculator moves forward in order: years first, then months, then weeks, then days. Order matters because months have unequal lengths — adding 1 month to January 31 produces February 28 or 29, not March 3.
Question: How many calendar days from March 2, 2026 to June 18, 2026?
Verify: enter March 2, 2026 as start and June 18, 2026 as end — the calculator returns 108 instantly.
Question: A product ships Thursday, July 9, 2026. The carrier promises 5 business days delivery. What is the estimated arrival date?
On a calendar-day basis, 5 days from July 9 gives July 14 — two days earlier. Business-day counting gives the accurate shipping estimate.
Measure the time between kickoff and launch, then compare the result with business days to see your real working window.
If an order ships on Thursday, July 9, 2026 and the carrier says 5 business days, weekday counting gives a more realistic delivery estimate.
Students can compare classes ending on May 22, 2026 with finals starting on June 1, 2026 to plan study time more accurately.
A 30-day notice starting September 1, 2026 can end on different dates depending on whether the process uses exclusive or inclusive counting.
Measure trip length, then move a departure date forward or backward by 7 or 14 days if prices or schedules change.
Add 90 days to a subscription date or 365 days to an annual renewal so reminders land on the correct date.
Some of the most frequent uses of a date calculator involve adding a fixed number of days to today's date. Use the Add/Subtract tab above for an exact result, or use the reference table below as a quick guide based on today's date of March 18, 2026.
| Days to Add | Calendar Date | Day of Week | Common Use |
|---|---|---|---|
| 30 days | April 17, 2026 | Friday | Invoice due dates, subscription renewals |
| 45 days | May 2, 2026 | Saturday | Contract notice periods, insurance claims |
| 60 days | May 17, 2026 | Sunday | Project milestones, trial periods |
| 90 days | June 16, 2026 | Tuesday | Quarterly reviews, probationary periods |
| 120 days | July 16, 2026 | Thursday | Visa timelines, insurance waiting periods |
| 180 days | September 14, 2026 | Monday | Medication refill eligibility, semi-annual reviews |
| 365 days | March 18, 2027 | Thursday | Annual renewals, warranty expirations |
Many notice periods are set at 30, 60, or 90 days. Lease terminations in California require 60 days notice for tenancies over one year. Employment contracts in New York often require 30-day notice. Use the Add/Subtract tab to find the exact deadline date, then verify it falls on a business day.
Standard shipping is usually quoted in business days: 3–5 business days domestic, 7–14 international. If an order ships on Friday, the first business day starts the following Monday. Use business-days mode to find the realistic delivery window rather than counting calendar days.
Insurance plans often restrict early prescription refills to 80–90% of the days supply — typically 24 or 27 days into a 30-day prescription. A 180-day supply may be refillable after 144 days. Enter your fill date and add the refill window to find your next eligible date.
Exclusive counting measures the gap between two dates. Inclusive counting treats both the starting day and ending day as part of the period. This is one of the biggest reasons people think a date calculator is wrong when it is actually following a different rule.
If a campaign runs from April 1 through April 30, the exclusive gap is 29 days between the dates, but the inclusive duration is 30 days because both dates count as active days. The same issue appears in hotel stays, rental agreements, legal notices, and software trials.
Use exclusive counting when you want the pure distance between two dates. Use inclusive counting when both boundary dates are active days in the schedule.
LiteCalc’s date and time tools simplify time tracking for any purpose. Whether you’re managing deadlines, event planning, or calculating durations, our calculators give you quick, accurate results that factor in every detail.
They support both U.S. and international date formats, ensuring compatibility for users worldwide. The system also accounts for leap years automatically, guaranteeing precise outcomes across all date ranges.
Use this calculator to determine project durations, payment cycles, delivery estimates, or academic term lengths. It’s trusted by professionals, educators, and planners for its speed, clarity, and reliability.
Our modern calendar—known as the Gregorian calendar—is the international standard for tracking days and years. Introduced in 1582 by Pope Gregory XIII, it replaced the Julian calendar to better align with the solar year, minimizing seasonal drift.
A standard Gregorian year has 365 days, while leap years add an extra day in February to keep the calendar in sync with Earth’s orbit. This correction ensures that annual events like equinoxes and holidays occur at consistent times each year.
Most of the world now uses the Gregorian calendar for civil, business, and scientific purposes. It’s the foundation for LiteCalc’s date calculations, ensuring your results reflect today’s universally accepted timekeeping system.
In the United States, federal holidays influence how business days are calculated. Days like New Year’s Day, Independence Day, and Thanksgiving are recognized nationwide, often excluded from work schedules and official business calendars.
Our business-day calculator feature helps you plan around weekends and public holidays automatically. This is ideal for payroll, project deadlines, and delivery planning where workdays—not total days—matter most.
Federal holidays in the U.S. typically include New Year’s Day (January 1), Memorial Day (last Monday in May), Independence Day (July 4), Labor Day (first Monday in September), Thanksgiving (fourth Thursday in November), and Christmas (December 25). Using LiteCalc, you can account for these automatically or adjust custom holidays as needed.
Add/subtract time from dates.
Find deadlines and project due dates.
Add days, weeks, or months.
Add or subtract hours and minutes.
Compare times worldwide.
Measure elapsed time between two dates.
The LiteCalc Date Calculator quickly finds the number of days between two dates or lets you add or subtract days from a specific date. It automatically adjusts for leap years and supports both calendar and business-day calculations.
Yes. Check the “Calculate business days only” box to exclude weekends. This feature is ideal for project schedules, payroll planning, or estimating delivery dates that skip non-working days.
Absolutely. The LiteCalc Date Calculator follows the Gregorian calendar system, automatically adjusting for leap years so your results are always accurate—even across multiple years.
LiteCalc uses the modern Gregorian calendar, which is the global standard for date and timekeeping. It was introduced in 1582 and includes leap years to keep seasons and calendar dates properly aligned.
Yes. Enter your start date, then choose to add or subtract any number of days. The calculator will instantly display the resulting date, perfect for setting deadlines or calculating future events.
Calendar days count every day, including weekends and holidays. Business days include only weekdays (Monday through Friday), excluding weekends and, optionally, U.S. public holidays.
Yes. The calculator provides total days between two dates, which you can easily convert to weeks or months. For detailed breakdowns, use the LiteCalc Time Duration Calculator for full year, month, and week conversions.
The business-day mode automatically skips weekends and allows manual adjustment for U.S. federal holidays like Thanksgiving, Christmas, and Independence Day, ensuring accurate workday counts.
The Gregorian calendar is the most accurate and widely accepted global system, correcting the drift found in older calendars like the Julian calendar. It ensures precise date alignment with the solar year for modern civil use.
As of March 18, 2026, adding 30 calendar days brings you to April 17, 2026 — a Friday. Because this changes daily, use the Add/Subtract tab above, enter today as the base date, select Add Time, type 30 in the Days field, and click Calculate to get the current answer instantly.
Yes. Enter the date your notice or contract term begins in the Add/Subtract tab, add the required number of days (e.g., 30, 60, or 90), and note the result. If the deadline must land on a business day — as many legal filings require — enable the business-days option so weekends are skipped. Always verify final legal dates with a qualified professional.
Yes. All LiteCalc tools, including the Date Calculator, Business Day Calculator, and Time Duration Calculator, are free to use online. No registration or download is required.