Date & Time
33 free tools — no signup required.
The Date & Time category collects tools for measuring durations, converting between time systems, and counting toward events. Use the Date Difference Calculator to find the span between two dates, the Time Zone Converter to line up meetings across regions, or the Age Calculator to work out an exact age in years, months, and days. The set also covers business-day counts, Unix timestamps, week numbers, countdowns, military-time conversion, and calendar converters for Islamic, Hebrew, and Buddhist systems. Each tool handles the awkward parts of date math, like leap years and month lengths, so scheduling work, planning travel, or tracking a deadline produces a dependable answer.
Featured Date & Time
Age Calculator
Find your exact age in years, months, and days.
Date Difference Calculator
Calculate years, months, days, hours, and weeks between any two dates.
Time Zone Converter
Convert wall-clock times between any IANA time zones, with DST handled correctly.
Days Until Date Calculator
Count the days from today to any future or past date.
Business Days Calculator
Count business days between dates, or add business days to a start date.
Unix Timestamp Converter
Convert Unix timestamps to dates and back, in any IANA time zone.
Countdown Timer
Live countdown to any future date and time, with days, hours, minutes, and seconds.
Days Between Dates
Calculate the exact number of days between any two dates.
Age Calculator
Find your exact age in years, months, and days.
Unix Timestamp Converter
Convert Unix timestamps to dates and back, in any IANA time zone.
Date Difference Calculator
Calculate years, months, days, hours, and weeks between any two dates.
Time Zone Converter
Convert wall-clock times between any IANA time zones, with DST handled correctly.
Business Days Calculator
Count business days between dates, or add business days to a start date.
Week Number Calculator
Find the ISO 8601 and US/Canada week number for any date.
Countdown Timer
Live countdown to any future date and time, with days, hours, minutes, and seconds.
Age in Days Calculator
Calculate your exact age in days, weeks, hours, minutes, and seconds.
Days Until Date Calculator
Count the days from today to any future or past date.
Days Between Dates
Calculate the exact number of days between any two dates.
Hours Calculator
Calculate hours and minutes between two times, with break deduction and overnight support.
Minutes to Hours Converter
Convert minutes to hours and back, in decimal and Hh Mm formats.
Seconds to Time Converter
Convert seconds to HH:MM:SS or days/hours/minutes/seconds, and back.
Military Time Converter
Convert between 12-hour AM/PM, 24-hour, and 4-digit military time formats.
Age on Date Calculator
Calculate how old someone will be (or was) on any specific date.
Leap Year Calculator
Check if any year is a leap year, with reason and the next leap year.
Day of Week Calculator
Find the day of the week for any date using Zeller's congruence.
Daylight Saving Time Calculator
Find DST spring-forward and fall-back transitions for any IANA time zone.
Work Hours Calculator
Add up multiple shifts with break deduction, overnight support, and optional pay rate.
Year Progress Calculator
See what percent of the year has elapsed, with day, week, and remaining days.
Time Until Event
Live countdown to any named future event with weeks, days, hours, minutes, seconds.
Months Between Dates
Count full months and remaining days between any two dates, with decimal months.
Weeks Between Dates
Count full weeks and extra days between any two dates, with decimal weeks.
Years Between Dates
Calculate years, months, and days between two dates, with decimal years.
Retirement Date Calculator
Find your retirement date from date of birth and target retirement age.
Jet Lag Calculator
Estimate hour shift, direction, and recovery days for a trip between two time zones.
World Clock
Live clocks for up to 12 IANA time zones, with offset and weekday.
Online Stopwatch
Browser stopwatch with start, pause, resume, lap, and reset at centisecond precision.
Meditation Timer
Meditation timer with optional interval bells, played silently if your browser blocks audio.
Easter Date Calculator
Find Western and Orthodox Easter dates for any year using the Meeus algorithms.
Islamic Calendar Converter
Convert between Gregorian and tabular Hijri dates using the Kuwaiti algorithm.
Hebrew Calendar Converter
Convert between Gregorian and Hebrew dates using the standard arithmetic Hebrew calendar.
Buddhist Calendar Converter
Convert Gregorian dates to Buddhist Era (Thai/Lao/Cambodian: BE = CE + 543) and back.
About Date & Time
Date and time tools handle calculations that are deceptively tricky by hand because months differ in length, leap years add a day, and time zones shift with daylight saving. These tools rely on the calendar rules and an accurate clock to count days, weeks, and months correctly, convert a wall-clock time from one zone to another, or translate between a human-readable date and a Unix timestamp measured in seconds since 1970.
Take the Date Difference Calculator. Between 15 March 2024 and 1 July 2024 there are 108 days, which it can also express as about 15 weeks and 3 days, or 3 months and 16 days. It accounts for the differing lengths of March, April, May, and June automatically, so you do not have to add up each month and risk an off-by-one error.
Results depend on the dates, times, and zones you enter, including how daylight saving applies on the day in question. For scheduling across regions, confirm the converted time near the event, since zone rules and observances can change, and double-check that start and end dates are entered in the order you intend. When a result feeds payroll, billing, or a legal deadline, recompute it on the day it matters so the latest daylight-saving and leap-year rules are applied to the calculation.
Frequently asked questions
- What are date and time tools used for?
- They measure durations between dates, convert times across zones, count business days, translate Unix timestamps, run countdowns, and convert between calendar systems, handling leap years and month lengths so the math stays correct.
- When should I rely on these tools?
- Use them for scheduling, deadline tracking, age and duration calculations, and cross-zone planning. For legally significant dates such as contracts or visas, confirm the result against the official source that governs the deadline.
- How accurate are the calculations?
- They apply standard calendar rules and an accurate clock, so day, week, and month counts are exact. Time-zone results depend on daylight-saving rules for the specific date, which the tools account for using current zone data.
- Are my dates and entries stored?
- No. Nothing is stored. Every calculation runs client-side in your browser, so the dates, times, and zones you enter stay on your device and never reach a server.
- Do these tools cost anything?
- No. Every date and time tool is free with no signup, account, or payment. Open a tool, enter your dates or times, and read the result.