Date & Time
How many workdays until the deadline? What's your baby's age in days? When should you sleep to wake up refreshed? Timestamp converters, countdown timers, age calculators, lunar calendars, world clocks, Pomodoro timers — all the date math you'd rather not do by hand.
Date & Time
Timestamp Conversion Tool
Free online timestamp converter for Unix timestamp to datetime format conversion. Supports millisecond and second timestamps, display multiple timezones.
Countdown Timer
Free online countdown timer to create custom countdowns. Set target time, reminder features, accurate to seconds, suitable for various scenarios.
Gaokao Countdown Tool
Gaokao countdown timer showing days, hours, minutes, and seconds until China's National College Entrance Examination, with automatic exam-year detection.
Baby Days Calculator
Free online baby days calculator to track days, weeks, and months since birth. Shows growth milestones, cherish every moment with your baby.
Due Date Calculator
Free online due date calculator based on your last period (LMP), IVF transfer, or ultrasound scan. See your due date, current pregnancy week and trimester.
Lifespan Calculator
Free online lifespan calculator to visualize your life progress. Calculate percentage of life lived based on birthdate and life expectancy.
Sleep Calculator
Free online sleep calculator built on 90-minute sleep cycles. Enter a bedtime or wake-up time to find the ideal moments to sleep and wake up refreshed.
Date Difference Calculator
Free online date difference calculator. Calculate days, weeks, months, years between two dates. Precise calculations with hours, minutes, seconds display.
Date Add/Subtract Calculator
Free online date add/subtract calculator. Add or subtract days, weeks, months, years from a date. Quick options for instant calculations.
Age Calculator
Free online age calculator. Calculate exact age, Chinese zodiac, total days lived, and days until next birthday from birth date.
Workday Calculator
Free online workday calculator. Count actual working days within a date range, excluding weekends and holidays. Perfect for project planning.
Lunar Calendar Conversion Tool
Free online Gregorian to Lunar calendar converter. Query zodiac, solar terms, traditional festivals. Supports 1900-2100 range, learn lunar calendar info.
Pomodoro Timer
Free online Pomodoro timer for scientific time management. 25 minutes of focused work, 5 minutes of short breaks, boost productivity and build focus habits.
Flip Clock
Free online flip clock with live time, 12/24-hour mode, optional seconds, and fullscreen display for desks, presentations, and focus sessions.
Chinese Dynasty Table
Complete chronological table of Chinese dynasties from Xia to Qing dynasty, with dates, founding emperors, and capital cities.
World Time Query
Free online world clock tool. View current time, date, and weekday for cities worldwide. Search city timezones and see offset from local time.
Time Unit Converter
Online time unit converter - convert between years, months, weeks, days, quarters, hours, minutes, seconds, and milliseconds. Accurate calculations, instant results.
Expiry Date Calculator
Free online expiry date calculator. Calculate expiration dates from production dates and shelf life, or estimate production dates from expiry dates.
What this category can do
Date and time tools handle timestamps, intervals, countdowns, workdays, ages, lunar dates, world clocks, time-unit conversion, sleep timing and expiry calculations. They differ from unit converters because calendar rules, time zones and daylight saving changes can affect the result.
Most tools process input in the browser when possible. For files, tokens, documents or network checks, review the selected tool before using sensitive data.
Common use cases
- Convert Unix timestamps from logs into local dates across time zones.
- Calculate date differences, workdays, ages, expiry dates or pregnancy due dates from exact dates.
- Check world city times, plan a countdown, estimate sleep cycles or run a Pomodoro session.
FAQ
Why do two results differ by one hour?
Daylight saving time or the selected time zone can shift local clock time. Use a region-specific zone when it matters.
Do workday tools include public holidays?
Usually they count weekdays unless a holiday option is available. Holiday rules vary by region.
What is the difference between a timestamp and a date?
A timestamp is an absolute moment. A date is how that moment appears in a particular time zone.
Can lunar calendar results be used officially?
Use them as a reference. For legal, ceremonial or administrative use, verify against an official calendar.