Date & time
Calculate calendar intervals without timezone surprises.
Date difference calculator
Count the calendar days between two dates, with leap years handled automatically and no timezone shift.
Open toolAdd days calculator
Add or subtract a whole number of calendar days from a date. Leap years and month boundaries are handled automatically.
Open toolWeeks Between Dates Calculator
Count complete weeks and remaining calendar days between two dates.
Open toolMonths Between Dates Calculator
Count complete calendar months between dates using an explicit end-of-month anniversary rule.
Open toolYears Between Dates Calculator
Count complete calendar years between dates, with February 29 anniversaries clamped to February 28.
Open toolAge Calculator
Calculate age in complete years, months and days on a date you choose.
Open toolSubtract Days Calculator
Find the calendar date a stated number of days before your starting date.
Open toolAdd Months Calculator
Add or subtract calendar months and handle shorter destination months explicitly.
Open toolAdd Years Calculator
Add or subtract calendar years, including leap-day dates.
Open toolBusiness Days Calculator
Count Monday-to-Friday working days between dates, excluding the holidays you enter.
Open toolAdd Business Days Calculator
Find a date after a stated number of working days, skipping weekends and your holiday list.
Open toolWeekday Calculator
Find the day of the week for a past or future Gregorian calendar date.
Open toolDay Of Year Calculator
Find a date’s day number within its year, accounting for leap years.
Open toolWeek Number Calculator
Find the ISO week number, ISO week-year and weekday for a calendar date.
Open toolIso Week To Date Calculator
Convert an ISO week-year, week number and weekday into a calendar date.
Open toolBirthday Calculator
Find the next birthday and the number of days remaining from a reference date you choose.
Open toolLeap Year Calculator
Check whether a Gregorian year is a leap year and whether it has 365 or 366 days.
Open toolDays In Month Calculator
Find the number of days in a month for the chosen Gregorian year.
Open toolTime Duration Calculator
Calculate elapsed seconds between timestamps with explicit UTC offsets.
Open toolClock Time Difference Calculator
Calculate elapsed minutes between two 24-hour clock times, with an explicit overnight option.
Open toolCountdown Calculator
Compare a target timestamp with a stated reference timestamp to find the time remaining.
Open toolUnix Timestamp Converter
Convert whole Unix seconds into a UTC timestamp.
Open toolJulian Date Calculator
Convert a timestamp to a UTC-based Julian date using the stated civil-time approximation.
Open tool