Time & Date Calculators
Nine tools for date arithmetic — the kind that looks simple until leap years, weekends and month lengths get involved.
Date maths is harder than it looks
Months have four different lengths, years have two, and "one month from 31 January" has no universally agreed answer. That is why the Age Calculator and the Date Difference count actual elapsed days rather than approximating with 30-day months — an approximation that drifts by nearly a week over a year. Every tool here uses the proleptic Gregorian calendar, including the rule that a century year is only a leap year if divisible by 400.
Elapsed time versus working time
For deadlines and delivery dates, calendar days are usually the wrong unit. The Working Days counts business days, skipping weekends, which is what contracts and service-level agreements normally mean by "within 10 days". The Date Difference gives the calendar answer. Choosing the wrong one is a common cause of a deadline being missed by exactly two days.
Durations, not dates
The Time Duration adds and subtracts hours and minutes — timesheets, shift patterns, total travel time — where the awkward part is carrying at 60 rather than 100. The Time Unit Converter converts between every time unit from milliseconds to millennia, and the Months, Weeks & Years handles the specific three-way conversion that comes up in pregnancy, tenancy and finance terms.
Live timing and a bit of fun
The Countdown Timer counts down to a moment and the Stopwatch counts up with lap splits — both run entirely in your browser and keep going if you switch tabs. The Generation Calculator is the light one: enter a birth year and see which generation cohort it falls into, and why the boundaries are argued about.