Date & Time Calculators
Work with dates and time effortlessly using our free online calculators. Calculate your exact age, find the difference between dates, convert time zones, track sunrise and sunset times, and explore moon phases. Our 23 date and time tools cover everything from simple day counting to astronomical calculations. Instant results, no signup required.
Date Calculations
View all →Age Calculator
Calculate your exact age in years, months, days, hours, and minutes from your birthdate.
Date Calculator
Add or subtract days, weeks, months, and years from any date to find a target date.
Day Counter
Count the number of days between two dates including or excluding weekends and holidays.
Day of the Week Calculator
Find out what day of the week any date falls on for past, present, or future dates.
Days Between Dates Calculator
Calculate the exact number of days between any two dates quickly and accurately.
Weeks Between Dates Calculator
Calculate the number of weeks and remaining days between any two dates.
Days From Now Calculator
Find the exact date that is a specific number of days from today.
Days Ago Calculator
Find the exact date that was a specific number of days before today.
Day of Year Calculator
Find the day number of the year (1-365) for any given date and days remaining in the year.
Week Number Calculator
Find the ISO week number for any date and see the start and end dates of any week.
What Day Calculator
Find what day of the week a specific date is or was on any calendar date.
Time Calculations
View all →Time Calculator
Add or subtract hours, minutes, and seconds to calculate time durations and differences.
Hours Calculator
Calculate the number of hours between two times for work tracking and time management.
Time Card Calculator
Calculate total work hours and pay from clock-in and clock-out times for weekly timesheets.
Time Zone Calculator
Convert times between any world time zones and find the current time anywhere.
Time Duration Calculator
Calculate the exact duration between two times in hours, minutes, and seconds.
Current Time Calculator
View the current time in any time zone around the world with live clock updates.
Time Difference Calculator
Calculate the time difference between two times or two time zones in hours and minutes.
Due Date Countdown Calculator
Count down the days, hours, and minutes until your due date or any important deadline.
Astronomy
View all →Sunrise Calculator
Find the exact sunrise time for any location and date based on geographic coordinates.
Sunset Calculator
Find the exact sunset time for any location and date based on geographic coordinates.
Dawn Calculator
Calculate civil, nautical, and astronomical dawn times for any location and date.
Moon Phase Calculator
Find the current moon phase and view a lunar calendar with full and new moon dates.
About Date & Time Calculators
Time-related calculations come up more often than most people realize. Whether you need to know your precise age for a form, figure out a deadline that falls 90 days from today, count the weeks between two events, or check what time the sun rises in your location, manual date and time math is error-prone and tedious.
Our Date Calculations tools handle everything calendar-related. The Age Calculator computes your exact age in years, months, days, hours, and minutes from your birthdate. The Date Calculator lets you add or subtract any combination of days, weeks, months, and years from a starting date. Additional tools like Days Between Dates, Day Counter, and Week Number Calculator make quick work of common date arithmetic.
The Time Calculations suite tackles time-specific problems. The Hours Calculator and Time Card Calculator help workers and managers track hours worked. The Time Zone Calculator converts times between any global time zones, while the Time Duration Calculator finds the exact span between two times. A Due Date Countdown tool keeps you on track for any upcoming deadline.
For those interested in natural phenomena, our Astronomy tools calculate sunrise, sunset, and dawn times for any location and date, plus a Moon Phase Calculator that shows the current lunar phase and upcoming cycles. All tools handle edge cases like leap years, varying month lengths, daylight saving transitions, and year boundaries.
Frequently Asked Questions
Does the age calculator account for leap years?
Yes, the age calculator fully accounts for leap years when computing your exact age. It correctly handles February 29 birthdays and adjusts day counts for each year in the range. The algorithm uses actual calendar arithmetic rather than averages, so results are always precise.
Can I calculate the number of days between two dates?
Yes, several tools handle this. The Days Between Dates Calculator gives you the exact count directly. The Date Calculator also shows the full breakdown in years, months, days, weeks, and hours. The Day Counter works for both past and future date ranges.
What date formats are supported?
Our date calculators accept standard date input through your browser's native date picker, which adapts to your locale. You can also type dates manually in most common formats. The calculators work with dates spanning many centuries.
How do the time zone conversions work?
The Time Zone Calculator uses the IANA time zone database, the same standard used by operating systems and programming languages worldwide. Enter a time and source zone, select your target zone, and get an instant conversion that accounts for daylight saving time rules.
Are sunrise and sunset times accurate for my location?
Our Sunrise and Sunset calculators use astronomical algorithms based on solar position equations. Enter your latitude and longitude (or use your browser's geolocation) and a date to get times accurate to within one to two minutes for most locations. Results account for atmospheric refraction.
What moon phases does the Moon Phase Calculator show?
The Moon Phase Calculator displays the eight standard phases: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent. It shows the current phase, illumination percentage, and dates for upcoming phases.