CalcChef tool collection
Date and Time Tools
Plan dates, compare time zones, and calculate durations without spreadsheet formulas or account sign-ups.
Start with these tools
Date Difference Calculator
Find the number of days between two dates, plus years, months and days, total weeks, ISO week numbers and business days minus six countries' public holidays.
Time Calculator
Add or subtract up to 10 durations in hours, minutes and seconds, or find the hours between two clock times, as HH:MM:SS, decimal hours and minutes.
Age Calculator
Age calculator: enter a date of birth to get your age in years, months and days, total days alive, days to your next birthday and the weekday you were born on.
Time Zone Converter
Convert a date and time from one time zone to another with daylight saving applied, then copy it as ISO 8601 or a Unix timestamp.
All Date and Time Tools
17 free browser-based tools
Age Calculator
Age calculator: enter a date of birth to get your age in years, months and days, total days alive, days to your next birthday and the weekday you were born on.
Age In Seconds
Age in seconds calculator: enter a birth date and time to see total seconds lived, days lived, a calendar breakdown, next birthday and planet ages.
Countdown Timer
Countdown timer for any length from 1 second to 7 days: type hours, minutes and seconds or pick a preset, pause and resume, and switch on a beep for the end.
Date Difference Calculator
Find the number of days between two dates, plus years, months and days, total weeks, ISO week numbers and business days minus six countries' public holidays.
Date Duration Calculator
Days, weeks, months and years between two dates, plus working days minus public holidays for the US, UK, Canada, Australia, Germany or France.
Day of Year
Find a date’s day number of the year (1 to 366), the days in that year and the days left, or turn a day number back into a date. It opens on today.
Days Until Countdown
Count the days from today to any date, or since a past one, with weeks, months, years, business days, a live countdown and a calendar file.
Event Date Planner
Plan an event from a start date or back from a deadline: milestones in working days, a buffer between them, weekends and holiday regions skipped.
Leap Year Checker
Check whether any year from 1 to 9999 is a leap year, with the divisible-by-4, 100 and 400 steps, February’s length and the nearby leap years.
Meeting End Estimator
Add agenda item lengths and the buffer between items to get a meeting's end time in any time zone, with each item's start and end and clock changes counted.
Project Timeline Calculator
Plan tasks with FS, SS, FF and SF dependencies and lag in working days; get the end date, slack, critical path, Gantt chart and CSV.
Stopwatch
Online stopwatch that shows hundredths of a second, records laps with the fastest and slowest marked, and keeps the time in your browser if you reload the page.
Time Calculator
Add or subtract up to 10 durations in hours, minutes and seconds, or find the hours between two clock times, as HH:MM:SS, decimal hours and minutes.
Time Zone Converter
Convert a date and time from one time zone to another with daylight saving applied, then copy it as ISO 8601 or a Unix timestamp.
Time Zone Meeting Planner
See when working hours overlap across a reference city and up to 7 others on a chosen date, with daylight saving applied, and share the plan as a link.
Time Zone World Clock
See the current time, date and UTC offset in up to 20 cities at once, with daylight saving from your browser's time-zone database. Search by city or country.
Working Days Calculator
Count business days between two dates, or add and subtract working days, skipping weekends and US, England and Wales, European, Australian or custom holidays.