Explore calculators in this category.
Generate a rolling 2-2-3 rota showing day/night balance, hours, and rest stretches based on your start date and shift length.
Preview a rolling 2-2-5-5 custody rotation with parent assignments, exchange timestamps, and night counts across any horizon.
Build a 4-3-3 shift rota, measure day/night balance, and flag gaps against night-duty preferences.
Calculate the future or past business date by skipping weekends—ideal for due dates, SLAs, and project schedules.
Find the calendar date that results after adding a specified number of weeks to a starting date.
Enter your birth date to determine your precise age in years, months, days, hours, and minutes.
Convert your age in years to an approximate number of days, accounting for leap years with the 365.25-day average.
Estimate how many hours you have lived based on age in years.
Convert an age expressed in years to total months. Enter the years and press Calculate.
Convert age in years to weeks.
Estimate total work hours in a year after vacation days.
Convert billable hours to 6-minute billing units.
Plan how many minutes of break you should take in a workday.
Find how many business days fall between two dates, excluding weekends.
Determine the weekday for any date.
Determine the day number within the year for a given date, accounting for leap years.
Find total daylight hours from sunrise and sunset times.
Enter a date and region to see how many days remain until the next daylight saving time change.
Count the number of days between two dates.
Return the number of days in a specific month and year, accounting for leap years.
Quickly convert any number of days into equivalent hours.
Convert a duration in days to total seconds. Enter the value and press Calculate.
Convert days into weeks (may be fractional).
Convert hours, minutes, and seconds into a single total in seconds.
Convert the time span of Earth years into their equivalent length in Mars years.
Project same-day shipping cutoffs, backlog, and overtime needed to hit e-commerce fulfillment SLAs.
Calculate the shared working-hour window across two or three time zones after converting schedules into UTC hours.
Convert hours to minutes.
Convert hours into total seconds.
Determine the ISO 8601 week number for a given date. Enter year, month, and day.
Translate jiffies—short intervals used in computing and electronics—into standard seconds.
Calculate the Julian Day Number for any given calendar date.
Work backward from a launch date to see when preparation must start, including buffers.
Find the time between connecting flights.
Identify whether a specific year includes an extra day (February 29) by applying the Gregorian leap year rules.
Forecast the observable portion of a low-Earth-orbit pass by combining altitude, elevation limits, and twilight conditions.
Compute time for light to travel a distance in space.
Convert Martian sols—Martian days about 39 minutes longer than Earth days—into their Earth-day equivalents.
See how many days your medication will last based on doses and interval.
Quantify monthly and annual meeting costs plus the dollars and hours you reclaim by trimming frequency or duration.
See how much of your workday is spent in meetings.
Convert standard days into metric weeks of 10 days.
Quickly convert microfortnights—a playful unit equal to one-millionth of a fortnight—into plain seconds.
Convert duration from milliseconds to days.
Convert minutes into decimal hours.
Convert minutes to seconds.
Calculate the number of minutes remaining until the next midnight using a 24-hour clock.
Approximate weeks contained in a number of months.
This calculator approximates the number of days until the next full moon. Enter a date to get an estimate based on the average lunar cycle.
Quickly assign rotating on-call coverage without spreadsheets. Enter your team, start date, and shift length to receive a sequenced schedule.
Calculate overtime hours beyond regular schedule.
Quickly translate the Pitman 2-2-3 pattern into staffing metrics. Provide your shift length, how many on-duty shifts each employee works within the 14-day cycle, the total cycle length, and the number of crews to view average weekly hours per employee and total daily staffed hours.
Calculate the total time required for a set of Pomodoro work sessions including short breaks.
Estimate when a PVC solvent-weld joint reaches full cure by combining start time and manufacturer-recommended dwell duration.
Find the calendar quarter by entering a month number from 1 to 12.
Project your mortgage rate-lock expiration, remaining buffer to closing, and potential extension costs.
Find the calendar year you can retire based on birth year and target retirement age.
Convert any duration in seconds into days with decimal precision and context on leap seconds, long projects, and scheduling.
Convert seconds to minutes.
Approximate how many 30-day months fit in a number of seconds.
Convert seconds to weeks.
Find which week of the semester a specific date falls into based on the term start date.
Estimate how many hours and days it will take to align your sleep schedule with a new shift using light exposure and caffeine strategies.
Convert sidereal days into Earth hours.
Find hours of sleep between bedtime and wake time.
Estimate eclipse obscuration and a practical viewing window by combining Sun and Moon apparent diameters with their centre separation.
Get a quick estimate of sunrise time based on latitude and the day of the year. The calculation uses a solar declination model to approximate the local sunrise in 24-hour decimal time.
Convert a time duration of hours and minutes to decimal hours for timesheets or billing.
Enter a date to see how many days remain until January 1 of the following year.
Find the time difference in hours between two locations by comparing their UTC offsets.
Enter a local meeting time and the UTC offsets to find the corresponding time in another time zone.
Add a contingency buffer to planned project days.
Convert two day-of-year values into the number of travel days so you can plan itineraries and project schedules with confidence.
Convert a calendar date to seconds since the Unix epoch.
Convert a UTC hour to local time using offset.
Get the Monday date for a given ISO week.
Find the week number within a month for a given date assuming weeks start on Sunday.
Find the number of weeks between two dates. Enter the start and end dates to see the difference expressed in weeks.
Convert weeks to days.
Convert any number of weeks into hours.
Convert weeks to approximate months using the average month length.
Convert weeks to seconds.
Translate hours of effort into standard workdays.
Convert working days into total calendar days.
Convert years to days using a 365-day year.
