Date and time
Date and time questions depend on a clear starting point and a stated convention. This collection separates calendar dates from elapsed durations. Counting dates, converting hours and calculating an age may use similar-looking inputs while answering different questions. Read whether an endpoint is included, whether a duration represents clock time or calendar time, and how the tool treats incomplete information before comparing two results.
Start with these tools
Age Calculator
Find exact age, total days, and the next birthday from two dates.
Date Calculator
Calculate duration between dates or add/subtract days from a starting point.
Date Difference Calculator
Find the exact calendar difference and total days between two dates.
Day Counter
Quickly calculate the exact number of days between two specific dates.
Day of Week Calculator
Find the weekday, day of year, ISO week number, and leap-year status.
Use unambiguous dates and confirm the intended timezone for work that depends on local clock readings. Calendar months do not all have the same length. A numerical duration does not by itself account for holidays, work schedules or employment rules. Where those matters affect a real decision, check the relevant calendar and agreement separately. Reproduce a result with a simple example spanning a known boundary, such as the end of a month, before using a longer interval. Saved links can help repeat a calculation, but dates relating to personal events may be sensitive. Review a link before sharing it and keep private records in an appropriate place.
dates
Age Calculator
Find exact age, total days, and the next birthday from two dates.
Date Calculator
Calculate duration between dates or add/subtract days from a starting point.
Date Difference Calculator
Find the exact calendar difference and total days between two dates.
Day Counter
Quickly calculate the exact number of days between two specific dates.
Day of Week Calculator
Find the weekday, day of year, ISO week number, and leap-year status.
Decimal to Time Calculator
Convert decimal hours to days, hours, minutes, and seconds.
Leap Year Checker
Quickly determine if a specific year is a leap year according to the Gregorian calendar.
Military Time Converter
Convert between 24-hour military time and 12-hour time with AM or PM.
Moon Phase
Visualize and track the current phase of the moon for any given date.
Sunrise Sunset Times Calculator
Estimate sunrise, sunset, solar noon, and day length from date, latitude, longitude, and UTC offset.
Time and Date Difference Calculator
Calculate signed elapsed time between two dates and clock times.
Time Conversion Calculator
Convert time intervals between subsecond, second, minute, hour, day, week, month, and year units.
Weekly Time Card
Track your weekly work hours, breaks, and estimated earnings accurately.
World Time Converter
Quickly convert your local time to any major global time zone.
duration
Hours to Days Converter
Convert hours to decimal days and days plus remaining hours.
Hours to Minutes Converter
Convert hours to minutes.
Hours Worked Calculator
Quickly calculate total shift duration minus break time for payroll or time tracking.
Milliseconds Converter
Quickly convert milliseconds into standard time units like seconds and minutes.
Minutes Converter
Easily convert minutes into hours or seconds for scheduling and timing.
Seconds Converter
Convert seconds to minutes and hours.
Time Arithmetic
Quickly add or subtract time values using a 24-hour clock format.
Time Duration Calculator
Calculate elapsed time between two clock times, including an optional next day.
Work Hours Calculator
Calculate daily billable hours and total pay for a shift.
Frequently asked questions
How do I choose a tool from Date and time?
Start with the quantity you need to solve for, then compare the required inputs and assumptions before entering values.
Are results in Date and time guaranteed?
No. Read the formula, limitations and reference information on the individual calculator. Entered example rates are not current offers or professional advice.
Can I save a calculation from Date and time?
The calculator pages support browser-local project and share controls. Shared links and exported files may contain your inputs.