Calculate dates, times, durations, time zones, and celestial events.
17 CalculatorsCalculate the number of business days between two dates, excluding weekends and US federal holidays. Essential for project planning and deadlines.
Calculate the exact number of days, weeks, months, or years between any two dates. Perfect for project planning and deadlines.
Find out what day of the week any date falls on — past, present, or future. Great for planning, historical research, and scheduling.
Find out how many days until any event, holiday, birthday, or deadline. Includes a countdown to major holidays.
Add or subtract hours, minutes, and seconds. Calculate time duration between two times, convert time units, and figure out what time it will be in X hours.
Convert times between any two time zones instantly. See UTC offsets, DST status, and whether it's business hours at your destination. Includes meeting planner for multiple cities.
Live times for 60+ cities worldwide with DST badges, business hours indicators, and night/day mode. Convert any time between zones instantly and find the best meeting time across multiple locations with the built-in meeting planner.
Calculate your exact age in years, months, weeks, days, hours, and minutes. Find out how many days until your next birthday.
Create a live countdown timer to any date and time. Share countdowns for events, launches, and important milestones.
Visualize your entire life as a grid of weeks. Every square is one week — past ones filled in, future ones waiting. Enter your birthdate and see exactly how much life you've lived and how much remains.
Watch humanity grow in real time. Live birth and death counters, regional breakdowns by continent, milestone tracker, and fascinating population stats updated every second.
Enter your birthdate and watch your entire life unfold in real time — every heartbeat, breath, step, dream, and moment. Your personal stats, ticking live.
How many Mondays do you have left until retirement, a milestone, or any target date? See your life's Monday timeline, what Monday number this week is, and all upcoming milestones at once. Based on the 4,000 Weeks concept.
Current moon phase with SVG diagram, moonrise and moonset times, illumination percentage, full moon calendar with supermoon and blue moon detection, and astrophotography planner. No API — pure astronomical algorithms.
See which planets are visible tonight from your location with rise & set times, brightness, and custom SVG planet diagrams. Includes monthly calendar and conjunction finder. No API — pure astronomical math.
Exact sunrise, sunset, solar noon, golden hour, and blue hour times for any location. Uses NOAA astronomical algorithms — no API, works offline. Includes full-year sun calendar and golden hour photography planner.
Find out how old you are on every planet in the solar system. Enter your birthday to see your age on Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto — plus your next planetary birthday and upcoming milestones.