Date & Time

Time zones, durations and timestamps.

41 tools

Age Calculator Calculate exact age in years, months, days and hours.
Birthday Paradox Probability of a shared birthday in a group of n.
Calendar Week Grid Render a month grid with ISO week numbers.
Countdown Timer Live countdown to any future date and time.
Cron Next-Fire Times Given a cron expression, list the next 10 fire times in UTC.
Date Add / Subtract Add or subtract days, weeks, months or years from any date.
Date Difference Calculator Difference between two dates in every common unit.
Date Format Converter Parse any date input and format it with a custom pattern.
Day of the Week Finder Find the day of the week, day of year and ISO week for any date.
Discordian Calendar Convert a Gregorian date to the Discordian calendar (5-day week, 73-day seasons).
DST Transition Lookup Find the next DST start/end for any IANA time zone.
Duration Formatter Format seconds or milliseconds as readable durations.
Easter Date Calculator Compute Western and Eastern Orthodox Easter for any year.
Equation of Time Compute the equation-of-time correction and approximate solar noon for any date.
Golden Hour Calculator Compute morning/evening golden and blue hour windows, plus civil/nautical/astronomical twilight.
Half-Birthday Calculator Given a birthday, find its six-month-after date.
Hebrew / Hijri / Persian Calendar Convert Gregorian dates to Hebrew, Hijri (Islamic) and Persian calendars.
ICS RRULE Builder Build an iCalendar RRULE string from frequency, interval, count or until, and BYDAY.
ISO 8601 Duration Parser Parse ISO 8601 duration strings into component parts.
ISO 8601 Duration Parser & Builder Parse ISO 8601 durations (P3Y2M10DT2H30M15S) and build canonical strings from numeric inputs.
ISO Week Number ISO 8601 week-of-year, day-of-year, and Monday-start week range.
Julian Date Converter Astronomical Julian Date (and MJD) ↔ Gregorian UT.
Maya Long Count Convert a Gregorian date to the Maya Long Count (baktun.katun.tun.winal.kin).
Meeting Time-Zone Planner Find overlapping working hours across multiple time zones.
Moon Phase Calculator Approximate moon age, fraction and phase for any date.
Pomodoro Timer 25-minute focus sessions with short and long breaks.
Recurring Event Calculator Generate recurring event dates from a start date and interval.
Relative Time Formatter Turn two timestamps into a friendly relative time phrase.
Roman Calendar Converter Convert a Gregorian date to Kalends / Nones / Ides notation and AUC year.
Saved Cron Schedules Bookmark cron expressions with a description.
Stardate Calculator Earth date ↔ Star Trek TNG-era stardate.
Stopwatch Start / stop / lap stopwatch with millisecond precision.
Sunrise / Sunset Calculator Compute sunrise, sunset and solar noon for any latitude / longitude / date.
Time Until… Live countdown to any future date and time.
Time Zone Converter Convert any date and time between time zones.
Time Zone Overlap Heatmap Visualize overlapping working hours across multiple time zones as a 24-hour grid.
Twilight Calculator Civil / nautical / astronomical twilight times for any date and location.
Working Days Calculator Count business days (Mon–Fri) between two dates.
World Clock Live current time in cities around the world.
Year Progress How far we are through the current year, month and day in real time.
Zodiac Finder Western and Chinese zodiac for any date.