Time & Date Calculators
Tools for age, date differences, and time conversions
All Time & Date Tools
Choose from 17 free time & date calculators
New Year Countdown
Live countdown to the New Year
Age Calculator
Calculate exact age from birthdate
Date Difference Calculator
Calculate days between two dates
Workdays Calculator
Calculate number of working days
Business Days Calculator
Calculate business days between dates
Countdown Calculator
Live countdown to any date and time
Days Until Calculator
Count days until any date
Time Zone Converter
Convert times between different time zones
Week Number Calculator
Find ISO week number for any date
Date to Day Calculator
Find day of week for any date
Time Duration Calculator
Calculate time between two times
Minutes to Hours Converter
Convert minutes to hours
Hours to Days Converter
Convert hours to days
Weeks to Months Converter
Convert weeks to months
Seconds to Minutes Converter
Convert seconds to minutes
Time Addition Calculator
Add time durations together
Time Subtraction Calculator
Subtract time durations
Complete Guide to Time & Date Calculators
Time calculations seem simple until they aren't. How many business days between now and a deadline? What day of the week is December 25th this year? How old are you in exact years, months, and days? Mental math breaks down quickly when you factor in leap years, varying month lengths, weekends, and time zones.
Our collection of 17 time and date calculators handles every temporal question you'll encounter — from simple unit conversions (minutes to hours) to complex calculations like business days between dates or time zone differences. Each tool accounts for the quirks of the calendar that make time math surprisingly tricky: months with 28, 30, or 31 days, leap years every 4 years (except centuries, unless divisible by 400), and the 24 time zones that wrap around the globe.
Whether you're planning a project timeline, calculating your exact age for a legal document, tracking days until an important event, or coordinating across time zones, you'll find the right tool here. Every calculation runs instantly in your browser with no sign-up required.
Which Time Calculator Should You Use?
Choose the right tool for your specific situation:
| Your Question | Best Calculator | What It Does |
|---|---|---|
| How many days until an event? | Days Until | Counts calendar days from today to any future date |
| How many business days between two dates? | Business Days | Excludes weekends, counts only Monday-Friday |
| What's my exact age? | Age Calculator | Precise age in years, months, days, hours, and minutes |
| How long between two dates? | Date Difference | Total days, weeks, and months between any two dates |
| What time is it in another city? | Time Zone Converter | Convert time between any two time zones worldwide |
| How long did something take? | Time Duration | Calculate hours and minutes between two clock times |
Common Time Calculation Workflows
Project Planning & Deadlines
- Count business days: Your contract says "delivery within 30 business days." Use the Business Days Calculator to find the exact calendar date — it's usually 6 weeks, not 4.
- Set milestones: Use the Date Difference Calculator to space checkpoints evenly across your project timeline.
- Track time spent: The Time Duration Calculator measures hours and minutes between start and end times for timesheet logging or billing.
International Coordination
- Schedule meetings: Use the Time Zone Converter to find overlapping business hours between London, New York, and Tokyo. Often there's only a 1-2 hour window.
- Plan travel: Calculate the date difference for your trip duration, then check what day of the week you arrive using the Date to Day Calculator.
- Track week numbers: European businesses often reference ISO week numbers. The Week Number Calculator converts between dates and week numbers instantly.
Personal Milestones
- Exact age for documents: Legal and medical forms sometimes need your age in exact years, months, and days. The Age Calculator handles leap years and month-length variations automatically.
- Countdown to events: Use the Countdown Calculator for a live, real-time countdown to a wedding, birthday, graduation, or any date that matters to you.
- Add or subtract time: Need to know the date 90 days from now? Use Time Addition. When was 6 months ago? Use Time Subtraction.
Frequently Asked Questions
What's the difference between calendar days and business days?
Calendar days include every day (Monday through Sunday). Business days count only weekdays (Monday through Friday), excluding weekends. 30 calendar days is about 4.3 weeks, but 30 business days is 6 full weeks. Legal deadlines, shipping estimates, and contract terms often specify which type they mean — getting it wrong can be costly.
How do leap years affect date calculations?
Leap years add February 29th every 4 years (with exceptions for century years not divisible by 400). This means the number of days between the same two calendar dates can differ by a day depending on whether a leap year falls within the range. All our calculators automatically account for leap years — you don't need to think about it.
Why does time zone conversion seem off by an hour sometimes?
Daylight Saving Time (DST) shifts clocks forward or backward by one hour in many regions, and different countries change on different dates. Our Time Zone Converter accounts for current DST status, but if you're planning a future event across time zones, double-check whether DST transitions happen between now and then.
What is an ISO week number?
The ISO 8601 standard defines week numbers where Week 1 is the week containing the first Thursday of January. This means a year has either 52 or 53 weeks, and some days at the start or end of a calendar year may belong to the previous or next year's week numbering. European businesses and international logistics commonly use ISO weeks for scheduling and reporting.
Can I calculate time durations that cross midnight?
Yes. The Time Duration Calculator handles overnight periods correctly. If you start work at 10:00 PM and finish at 6:00 AM, it correctly calculates 8 hours. The Time Addition and Subtraction calculators also handle wraparound past midnight or below zero.