All Date Calculators
All 152 working calculators, across 18 categories. Find the dates, schedules and answers you need.
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Time formats & conversions 4 calculators
Time Calculator
Add or subtract durations, multiply or divide time, calculate overnight differences and move clock times forward or backward. Inspect the working, then copy, print or export.
Open calculatorMilitary Time Converter & Printable Chart
Convert military, 24-hour and AM/PM clock times. Print an hourly or half-hour chart, convert a list and export the results.
Open calculatorTime Duration Converter
Convert seconds, minutes, hours, days and weeks to decimal units or H:MM:SS. Keep long durations intact and convert a whole list.
Open calculatorDecimal Hours Converter
Convert hours and minutes to decimal hours, or decimals back to H:MM:SS. Copy, print or export a list of timesheet durations.
Open calculatorSun, Moon & outdoors 11 calculators
Sunrise & Sunset Planner
Find local sunrise, sunset, dawn, dusk and daylight for a city and date. Compare a month, print a sun calendar or download its events.
Open calculatorMoon Phase Calendar & Full Moon Finder
See the Moon phase and illumination for today or any date, find the next full or new moon, and print or export a monthly calendar.
Open calculatorMoonrise & Moonset Planner
Find local moonrise, moonset and time above the horizon. Browse a month of Moon times, phases and illumination, then print or export.
Open calculatorGolden & Blue Hour Planner
Plan photography with golden and blue hour windows for any city and date. Compare a month and print or export the light windows.
Open calculatorSeasons Date Calculator
Find spring, summer, autumn and winter start dates for either hemisphere. View equinoxes and solstices in your time zone and export calendar reminders.
Open calculatorDark-Sky Calendar Planner
Find nighttime windows with the Sun below your chosen twilight threshold and, optionally, the Moon below the horizon. Rank up to 31 nights by usable duration.
Open calculatorDaylight Change Calculator
Compare daylight across a date range, see daily gains or losses and find the first date meeting your daylight-hours target for a chosen location.
Open calculatorEclipse Visibility & Date Finder
Find solar and lunar eclipses available above your local horizon, with phase contacts and calendar windows for a selected date range.
Open calculatorMeteor Shower Observing Planner
Compare observing windows near ten major 2027 meteor-shower peaks using local darkness, Moon position and radiant altitude.
Open calculatorSun Alignment Date Finder
Find dates and time windows when the Sun matches your chosen true azimuth and elevation within an explicit angular tolerance.
Open calculatorTide Window Calendar
Find predicted high and low tides at ten NOAA stations, filter by height and local time, and export planning windows around matching events.
Open calculatorWorkdays & planning 15 calculators
Work Hours Calculator
Calculate work hours between dates and times, subtract unpaid breaks and compare wall-clock or actual elapsed hours across daylight-saving changes.
Open calculatorTime Card Calculator
Add dated clock-in and clock-out intervals, overnight shifts and unpaid breaks. See daily and weekly hours, custom overtime totals, and export your time card.
Open calculatorBusiness Days Calculator
Count working days between dates with your own workweek and excluded holidays. Choose whether to include each endpoint and see a clear count breakdown.
Open calculatorAdd Business Days
Add or subtract working days from a date. Customize weekends, exclude holidays, decide whether the start counts, and see the resulting date and skipped days.
Open calculatorAdd Months & Years
Add or subtract years, months, weeks and days from a date. Choose clamp, preserve month-end or reject missing dates, and inspect each calculation step.
Open calculatorHalfway Date Calculator
Find the halfway date between two dates or a chosen percentage milestone. Compare quarter points, follow forward or backward ranges, and export the results.
Open calculatorRotating Shift Calendar
Build a rotating shift calendar from a custom day, night and off pattern. Preview up to a year, count scheduled hours and export an all-day roster.
Open calculatorBusiness Hours Calculator
Calculate working hours between dates and times. Set working weekdays, lunch breaks and holidays, with daily totals and optional time-zone-aware elapsed hours.
Open calculatorAdd & Subtract Business Hours
Add or subtract working hours and minutes from a date. Skip weekends, lunch and holidays, calculate a deadline and inspect the working periods consumed.
Open calculatorTeam Capacity Calculator
Plan team capacity using each person's working days and available hours. Subtract dated absences and team closures, with daily and individual totals.
Open calculatorAppointment Capacity Calculator
Fit appointments into opening hours around breaks and blocked time. Include before and after buffers and see exact slots plus unusable fragments.
Open calculatorShift Rest Gap Calculator
Check elapsed rest between dated shifts for multiple people. Find overlapping shifts and gaps below a minimum you choose, with time-zone and DST handling.
Open calculatorOn-Call Rotation Calculator
Build an all-day on-call roster with named people, rotation length and unavailable dates. See substitutes, uncovered dates and each person's coverage load.
Open calculatorAttendance Days Calculator
Calculate attendance from scheduled weekdays and dated absences. Find how many more attended dates you need to reach a percentage target.
Open calculatorHybrid Office-Day Planner
Plan office dates around a weekly quota, preferred weekdays, committed dates and leave. See weeks where the required office attendance cannot fit.
Open calculatorAges & date spans 5 calculators
Age Difference Calculator
Compare two birth dates in years, months, days and exact total days, and see both people's ages on the same date.
Open calculatorDate of Birth Calculator
Find possible birth dates from an age recorded on a known date. Use completed years or a precise years, months and days breakdown.
Open calculatorAge Calculator
Calculate calendar age on a past, present or future date. See years, months, days, total weeks and the next birthday, with an explicit February 29 convention.
Open calculatorDate Duration Calculator
Find the calendar duration between dates in years, months and days. Compare total days and weeks, inspect the month anchor, and handle reversed date ranges.
Open calculatorWeeks Between Dates
Calculate weeks between two dates, including leftover days and decimal weeks. Choose inclusive counting and copy the result with its counting convention.
Open calculatorEveryday date math 3 calculators
General Date Calculator
Count calendar days between two dates or add and subtract days. Choose inclusive counting, reverse a range, and copy the result.
Open calculatorDate Range Overlap Calculator
Compare multiple date ranges. Find shared days, overlap across all ranges, unique coverage and uncovered gaps, with explicit inclusive or exclusive end dates.
Open calculatorRecurring Date Generator
Generate daily, weekly, monthly or yearly dates. Choose weekdays, nth-weekday patterns and exclusions, then export a CSV or an all-day recurring calendar.
Open calculatorHome & hobbies 8 calculators
Sleep Schedule Calculator
Plan a bedtime or wake-up time from your chosen sleep duration and time-to-fall-asleep estimate, including daylight-saving changes.
Open calculatorReading Finish Date Calculator
Find when you will finish a book or the daily pages needed for a deadline. Choose reading weekdays, skip dates and export a page-by-page schedule to your calendar.
Open calculatorPet Food Reorder Calculator
Estimate when pet food will run short and when to reorder. Combine multiple pets' daily consumption with stock, delivery lead time and a safety buffer.
Open calculatorHome Maintenance Calendar
Plan maintenance for multiple tasks using calendar intervals, meter readings or both. See what is due first and estimate usage-trigger dates from your daily rate.
Open calculatorChore Rotation Calendar
Assign recurring household chores across available people. Include previous turns, rotate ties and report any dates where nobody can take a chore.
Open calculatorMoving Timeline and Overlap
Compare old and new possession dates, utility timing and a moving date. Schedule dependent preparation tasks backwards with clear buffer days.
Open calculatorRental Occupancy Calendar
Count occupied and available nights from several stays. Apply cleaning buffers and blackout nights, and expose overlapping reservations.
Open calculatorRenovation Sequence Planner
Schedule dependent renovation tasks while separating active working days from full calendar-day waits. Inspect the earliest next stage after each task.
Open calculatorPay & leave 8 calculators
PTO Accrual Calculator
Project paid time off from your opening balance, accrual schedule, optional cap and planned leave. See the dated ledger and when a target balance is first reached.
Open calculatorVacation Days Needed Calculator
Find the leave needed for a trip with partial departure and return days. Exclude work holidays and lunch, then apply hourly, half-day or full-day charging.
Open calculatorPayday & Payroll Calendar
Generate weekly, biweekly, semimonthly or monthly paydays. Set period lag, processing cutoffs and holiday adjustments, then download your payroll calendar.
Open calculatorHoliday Leave Planner
Find your longest break with a leave-day budget. Combine weekends, custom workdays and holidays, compare dates and export the leave days to your calendar.
Open calculatorLeave Carryover Calculator
Track expiring leave balances and planned time off. Use the earliest-expiring balance first and see unused expiry losses or leave that cannot be covered.
Open calculatorProrated Leave Calculator
Calculate a partial-year leave allowance from employment dates, the leave year and your work-pattern factor. Show the day fraction and chosen rounding rule.
Open calculatorCredited Service Date
Combine employment periods and manual day credits to calculate credited service, an equivalent continuous start date and the next anniversary.
Open calculatorTeam Leave Coverage
Check team leave against a minimum daily staffing level. Compare individual workweeks and overlapping absences to find uncovered dates.
Open calculatorCalendar lookups 5 calculators
Fiscal Calendar Calculator
Find a date's fiscal year, quarter and month with a custom year-start month. Compare start-year and end-year labels and inspect every monthly boundary.
Open calculatorISO Week Number Calculator
Find the ISO week number, week-year and Monday–Sunday range for a date, or convert an ISO week and weekday back to a calendar date.
Open calculatorDay of Year Calculator
Convert a date to its day-of-year number or a year and day number back to a date. See YYYY-DDD, leap-year length, days remaining and a month reference table.
Open calculatorWeekday Calculator
Find the weekday for a date or the first, second, third, fourth, fifth or last weekday of a month. Preview the same pattern across a whole year.
Open calculatorRetail Calendar Calculator
Build a week-based retail year with twelve periods, 52 or 53 weeks and prior-year week comparisons. Choose your closing anchor and week convention.
Open calculatorTravel & booking 8 calculators
Trip Nights Calculator
Count hotel nights across multiple stays. Check checkout dates, spot unbooked nights or overlapping reservations, and download an itinerary calendar.
Open calculatorLayover Calculator
Check multiple flight connections using dated local arrivals and departures. Convert time zones and subtract your connection and transfer allowances.
Open calculatorBooking Window Calculator
Find when reservations open under rolling-day, rolling-month or monthly-batch rules. Show the release in the provider's time zone and your own.
Open calculatorAnnual Travel Days Log
Count unique travel dates in a year and allocate shared dates between countries or places. Combine overlapping journeys without counting a date twice.
Open calculatorMulti-City Itinerary Date Checker
Check dated travel legs across time zones, compare accommodation intervals and reveal overlaps or unfilled time between journeys.
Open calculatorTrip Cancellation Window
Turn entered cancellation terms into dated penalty windows. Resolve each boundary in the provider's local time zone and export reminders.
Open calculatorPassport Validity Calculator
Compare passport dates with a named Schengen short-visit rule or your selected validity interval, showing the required expiry and margin.
Open calculatorSchengen Days Calculator
Check a proposed Schengen short stay against each rolling 180-day window, using your previous visits and inclusive entry and exit dates.
Open calculatorSports & training 6 calculators
Running Pace & Race Split Calculator
Calculate running pace, finish time or distance. Plan even or negative splits for a 5K, 10K, half marathon, marathon or custom run, then copy, print or export your plan.
Open calculatorTraining Plan Start Date Calculator
Work backwards from race day to place an existing training plan on your calendar. Choose the first weekday, plan length and full-date buffer.
Open calculatorRace Calendar & Spacing Planner
Compare races chronologically, flag gaps below your spacing rule and see preparation windows that reach a preceding event.
Open calculatorSports Age Group Calculator
Calculate age on an organizer's cutoff date and compare it with entered division bands. Choose the Feb 29 convention and reveal ambiguous overlaps.
Open calculatorTraining Cycle Calendar
Lay out a repeating sequence of training and rest steps. Anchor the cycle to a date and choose whether unavailable dates pause or consume a step.
Open calculatorHiking Departure Time Planner
Find a departure time from your route-duration estimate, breaks and a buffer before sunset, civil dusk or an entered return time.
Open calculatorSchool & study 8 calculators
School Days Calculator
Count school days and remaining instructional days using term dates, custom weekdays, school breaks and half-days. View monthly totals and export the breakdown.
Open calculatorStudy Schedule Calculator
Allocate study hours across competing exam dates and your available days. Prioritize earlier deadlines and see workloads that cannot fit before an exam.
Open calculatorAcademic Week Calculator
Find a date's week within an academic term. Choose the week boundary, enter term breaks and decide whether complete break weeks pause the numbering.
Open calculatorSpaced Review Calendar
Schedule reviews for multiple learning items with custom day offsets and a daily minute cap. Keep original due dates visible when reviews are deferred.
Open calculatorA/B Timetable Rotation
Build a dated A/B or custom school rotation. Choose whether a closure pauses the cycle or advances it without holding classes.
Open calculatorClass Session Scheduler
Find actual class dates and the final session from weekly meetings, cancellations and make-ups. Export timed classes with explicit time-zone rules.
Open calculatorCourse Completion Date
Plan when you can finish remaining course hours with an uneven weekly schedule, breaks and dated capacity overrides. See the weekly study totals.
Open calculatorGraduation Term Planner
Find the earliest feasible completion term for remaining courses using term offerings, prerequisite chains and your credit limit in each term.
Open calculatorData & developer tools 16 calculators
Unix Timestamp Converter
Convert Unix timestamps to dates or dates to epoch time. Batch up to 100 values with seconds, milliseconds, microseconds, nanoseconds and explicit time zones.
Open calculatorDate List Comparison
Compare two lists of date labels. Find shared dates, dates only in each list, their unique union and duplicate entries, with a chronological breakdown.
Open calculatorCron Schedule Calculator
Preview the next runs of a five-field cron expression in a chosen time zone, including skipped and repeated daylight-saving clock times.
Open calculatorDate Format Converter
Convert a list of dates between declared formats, ISO dates and offset timestamps. Keep invalid rows and ambiguous month/day values visible.
Open calculatorDiscord Timestamp Generator
Create Discord timestamp markup from a date, clock time and time zone. Compare all nine display styles and copy the selected timestamp.
Open calculatorExcel Date Converter
Convert Excel serial numbers to dates and times, or encode a workbook date, using the 1900 or 1904 date system.
Open calculatorJulian Date Converter
Convert astronomical Julian Date or Modified Julian Date to a Gregorian UTC date/time, or calculate JD and MJD from a date.
Open calculatorNTP Timestamp Converter
Decode NTP seconds and fraction fields with an explicit era, or encode a UTC date/time into an NTP timestamp.
Open calculator.NET Ticks Converter
Convert .NET DateTime ticks to dates or encode a date/time without losing integer precision. Choose UTC or unspecified wall-clock interpretation.
Open calculatorGPS Time Converter
Convert GPS week and seconds to UTC or GPS-scale date/time. Resolve truncated week numbers with an explicit rollover cycle.
Open calculatorISO Duration Calculator
Read an ISO 8601 duration and apply it to a local date/time, or convert fixed units to elapsed seconds without an anchor.
Open calculatorMissing Date Finder
Find missing dates in a pasted list against a daily, selected-weekday or every-N-days calendar. Report duplicates, invalid rows and unexpected dates.
Open calculatorMongoDB ObjectId Timestamp Decoder
Decode the timestamp field from MongoDB ObjectIds. Compare UTC and a selected local zone while preserving invalid input rows.
Open calculatorULID Timestamp Decoder
Extract UTC and local timestamps from ULIDs, with millisecond precision and validation of the Crockford Base32 alphabet.
Open calculatorUUID Timestamp Decoder
Decode RFC-variant UUID v1, v6 and v7 timestamp fields. Identify other versions without inventing a creation date.
Open calculatorWindows FILETIME Converter
Convert Windows FILETIME values to UTC dates and back, preserving exact 100-nanosecond precision in decimal or hexadecimal.
Open calculatorHolidays & world calendars 12 calculators
Easter Date Calculator
Compare Western and Orthodox Easter dates for up to thirty years, with Good Friday, Easter Monday, Ascension and Pentecost dates.
Open calculatorJulian / Gregorian Date Converter
Convert between Julian and Gregorian calendar dates, including Julian century leap days, using explicit proleptic calendar rules.
Open calculatorJapanese Era Date Converter
Convert Gregorian dates to Japanese era notation or back, respecting the exact transition dates between eras.
Open calculatorThai Buddhist Year Converter
Convert modern Thai Buddhist Era dates to Gregorian dates and back using the January-start solar-calendar convention.
Open calculatorCoptic Date Converter
Convert Gregorian and Coptic civil dates in either direction, including the short thirteenth month and leap-day validation.
Open calculatorEthiopian Date Converter
Convert Gregorian and Ethiopian civil dates in either direction, with month names and validation of the thirteenth month.
Open calculatorHebrew Date Converter
Convert Gregorian and Hebrew dates in either direction, including leap-year Adar months and the original date's sunset boundary.
Open calculatorHebrew Birthday & Anniversary Calendar
Find future Gregorian dates for a Hebrew birthday or personal anniversary, with explicit Adar and short-month rules.
Open calculatorYahrzeit Calculator
Plan Hebrew memorial anniversary dates and preceding sunset evenings, with an explicit Adar custom and calendar export.
Open calculatorPersian Date Converter
Convert Persian Solar Hijri and Gregorian dates in either direction, with weekday labels and strict date validation.
Open calculatorHijri Date Converter
Convert Gregorian and Hijri dates using an explicitly selected tabular civil or Umm al-Qura calendar method.
Open calculatorChinese Lunar Date Converter
Convert Chinese lunar and Gregorian dates, preserve leap-month identity, and plan a lunar anniversary in another year.
Open calculatorProjects & operations 10 calculators
Backward Scheduling Calculator
Work backward from a project deadline. Set task durations, working weekdays, holidays and buffer days, then check your latest start date and export the plan.
Open calculatorSprint Calendar Calculator
Generate numbered sprint intervals from an anchor date. Count available working dates, include shutdowns and mark releases every chosen number of sprints.
Open calculatorEvent Timeline Calculator
Build a timed event run of show with setup, activities, breaks and teardown. Check fixed cues, venue access and closing overruns in a chosen time zone.
Open calculatorProject Finish Date and Critical Path
Calculate a project's earliest finish from task durations, predecessors and a work calendar. See critical tasks, one critical path and task slack.
Open calculatorLead-Time Date Estimator
Estimate a finish date from historical job durations and your work calendar. Compare nearest-rank percentiles, sample size and the observed range.
Open calculatorMaintenance Window Fit
Check whether dependent maintenance tasks and a buffer fit allowed outage windows. Compare elapsed time, local blackouts and daylight-saving changes.
Open calculatorRelease Schedule Planner
Plan recurring release dates with testing and review gates. Apply a working calendar and identify collisions with entered freeze periods.
Open calculatorWeighted Milestone Calendar
Place project milestones using unequal phase weights, total effort and available working hours. See partial-day milestones and capacity shortfalls.
Open calculatorSLA Deadline Calculator
Calculate a service deadline from opening time, a priority-minute target, working hours and pauses. Check consumed and remaining service budget.
Open calculatorProduction Batch Schedule
Schedule production batches on named machines with availability dates, daily working hours, rates and setup times. Keep unscheduled work visible.
Open calculatorBills & renewals 8 calculators
Invoice Due Date Calculator
Calculate invoice payment dates for Net 15, 30, 60 or custom terms and month-end terms. Set weekend adjustments, holidays and an optional discount window.
Open calculatorInvoice Aging Calculator
Group outstanding invoices into current, 1–30, 31–60, 61–90 and 91+ day buckets. See overdue balances and individual invoice details on any report date.
Open calculatorSubscription Billing Calendar
Plan subscription renewal periods after a free trial. Preserve month-end anchors, compare pause policies and generate cancellation notice reminders.
Open calculatorFree-Trial Cancellation Planner
Calculate a trial cancellation reminder from entered trial terms, a cutoff time zone and an elapsed-hour safety lead. Export the reminder to a calendar.
Open calculatorReturn Window Calculator
Estimate a return deadline from purchase or delivery, an inclusive-day rule and an optional policy extension. Check how much time remains on a chosen date.
Open calculatorWarranty Coverage Calendar
Compare component warranty dates from purchase or installation. Add separate extension periods to see expiry dates and gaps in the entered coverage timeline.
Open calculatorRenewal Notice Window
Find earliest and latest notice receipt dates, then work backwards for delivery. Preview recurring renewals with anchored month anniversaries.
Open calculatorRetention and Disposal Review Planner
Plan record-review dates from entered retention periods and triggers. Keep active holds blocked and account for released holds without deleting anything.
Open calculatorGardening 7 calculators
Seed-Starting Calculator
Plan indoor seed starting or direct sowing from your frost-free reference and seed-packet timings. See germination, hardening and transplant dates with calendar export.
Open calculatorGrowing Season Calculator
Count usable dates between entered frost boundaries and compare a crop's maturity range. See whether all, part or none of the range fits the season.
Open calculatorHarvest Date Calculator
Estimate harvest dates from planting, or work backwards from a desired harvest. Distinguish maturity measured from sowing versus outdoor transplanting.
Open calculatorSuccession Planting Calculator
Plan repeated planting batches and their harvest windows. Find the last fully fitting planting, partial season fits and overlapping harvest windows.
Open calculatorFall Planting Calculator
Work backwards from expected fall frost to planting deadlines using a maturity range, your seasonal adjustment and a full-date harvest buffer.
Open calculatorGarden Bed Turnover Planner
Compare crop occupancy and clearing periods across garden beds. Find free date windows long enough for your next planting and flag overlapping use.
Open calculatorSeed Stratification Planner
Count backwards from a sowing date through your seed's ordered treatment stages. Build warm, cold or other treatment reminders using supplied durations.
Open calculatorFamily & events 10 calculators
Childcare Coverage Gaps
Find uncovered care intervals from a required time window and several carers' availability. Allow travel buffers and combine overlapping coverage.
Open calculatorConference Track Scheduler
Check a multi-track conference timetable for room conflicts, shared speakers, changeover buffers, breaks and speaker availability.
Open calculatorFamily Free-Date Finder
Find consecutive dates when everyone is available. Combine multiple availability ranges per person, apply exceptions and rank the longest shared windows.
Open calculatorParenting Rotation Calendar
Turn an agreed A/B pattern into a dated parenting calendar with a daily handoff boundary, time zone and specific-date overrides.
Open calculatorParenting Time and Overnight Count
Count parenting hours, reporting-period shares and overnights from entered care intervals. Apply overrides and expose unassigned time.
Open calculatorRSVP Cutoff Planner
Work backwards from a vendor's final-count date through finalization, late replies, response time and invitation delivery.
Open calculatorSchool Pickup Rota
Assign school pickup dates using adults' available weekdays, maximum turns and exceptions. Show assignment totals and unfilled dates.
Open calculatorTicket Sales Calendar
Plan ticket-sale phases relative to an event date. Find overlapping phases, gaps and blackout dates without changing your entered timing.
Open calculatorTournament Fixture Calendar
Build a single round-robin fixture plan with multiple courts, daily availability, match lengths and rest between each team's matches.
Open calculatorHoliday Conflict Planner
Compare candidate event dates across published country and region holiday calendars. Include your own cultural dates and review coverage and tentative status.
Open calculatorCreative hobbies 8 calculators
Cross-Stitch Completion Calculator
Estimate a cross-stitch completion range from remaining stitches, slower and faster measured paces, weekly sessions and unavailable dates.
Open calculatorWriting Deadline Planner
Plan remaining words around available writing dates. Balance a deadline target or use your daily pace, then reserve separate dates for revision.
Open calculatorHomebrew Schedule Planner
Arrange your supplied brewing-stage durations on a calendar and check named equipment against other bookings. Export stage-start reminders.
Open calculatorKnitting Completion Calculator
Estimate a knitting finish date from remaining sections, rows or repeats, measured minutes per unit and your weekly session calendar.
Open calculatorPractice Goal Date Calculator
Find when your practice-hour goal fits your weekly sessions. Exclude breaks, override individual dates and divide practice time between activities.
Open calculatorQuilt Completion Planner
Plan quilt completion from cutting time, remaining blocks and finishing stages. Fit the work into weekly sessions and see unscheduled minutes.
Open calculatorSourdough Baking Schedule Planner
Plan backwards from a bake-finished time using your observed stage-duration ranges. Compare shorter and longer schedules and flag active work during quiet hours.
Open calculatorPottery Project Calendar
Map estimated drying onto available bisque, glazing and glaze-firing dates. Find collection dates from studio-supplied availability and show sequences that do not fit.
Open calculator