Date & Time Calculators
Age, date difference, timesheets, countdowns, and time zone calculators.
Date and time calculations appear everywhere — project deadlines, age milestones, payroll hours, travel across time zones, and countdowns to important events. Our date & time calculators handle calendar math, business day counts, duration formatting, and timezone conversions in seconds.
Stop counting days on your fingers or wrestling with spreadsheet formulas. Enter two dates to find the difference, add or subtract intervals, convert Unix timestamps, or calculate exact age down to the day.
HR teams, project managers, travelers, parents, and event planners all rely on accurate date math. Every tool below is free, instant, and works on mobile and desktop.
Age & milestones
Exact age from date of birth, age in total days, and countdown timers to future events.
Date arithmetic
Days between dates, add/subtract days or months, week numbers, quarters, and leap year checks.
Work & payroll
Working days between dates (excluding weekends), time card totals, and hours/minutes calculators.
Time zones & formats
Convert between time zones, military (24-hour) time, Unix timestamps, and world clock views.
All Date & Time Tools
17 free calculators — click any tool to open it instantly.
Age Calculator
Calculate exact age in years, months, days, hours, and minutes — from birth to today or any custom target date.
Date Difference
Calculate the exact number of days, weeks, months, and years between any two dates.
Working Days Calculator
Count the number of business (working) days between two dates, excluding weekends.
Time Zone Converter
Convert a time from one time zone to any other time zone around the world.
Days Until Calculator
Find out exactly how many days, hours, and minutes until any future date or event.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds.
Week Number Calculator
Find the ISO week number for any date, or determine which date a given week number starts on.
Date Add/Subtract
Add or subtract days, weeks, months, or years from any date to find a past or future date.
Time Duration Calculator
Calculate the duration between two times, or add/subtract hours, minutes, and seconds to a given time.
Hours Calculator
Add and subtract hours and minutes for timesheets, payroll, and project time tracking.
Military Time Converter
Convert between 12-hour (AM/PM) and 24-hour (military) time formats instantly.
Leap Year Calculator
Check if any year is a leap year and find the next or previous leap years from any date.
Time Card Calculator
Calculate total work hours, overtime, and pay from clock-in/clock-out times for weekly timesheets.
Countdown Timer
Set a countdown timer for any duration — minutes, hours, or days — with alerts when time is up.
World Clock
View the current time in multiple cities and time zones around the world simultaneously.
Age in Days Calculator
Find your exact age in total days, hours, minutes, and seconds since birth — updated in real time.
Quarter Calculator
Find which fiscal or calendar quarter a date falls in, and get quarter start/end dates for any year.