Dates & time
tools and calculators.
30 practical tools with clear inputs and explanations. Choose a tool below, or explore a role-based toolbox for a collection that fits your day.
Date difference
Count the days between a beginning and a big moment.
Date range generator
Create a dated list at fixed day intervals, with weekday or weekend filtering.
Recurring date planner
Generate anchored weekly, monthly or yearly dates with a clear month-end policy.
Nth weekday of a month
Find the first to fifth, or last, chosen weekday in a month.
Add or subtract working days
Move a date using your chosen weekdays and excluded-date list.
Work calendar hours
Summarise eligible dates and assumed working hours by month.
Fiscal year & quarter
Find the year and quarter boundaries for a fiscal year starting in a chosen month.
Date range overlap
Find shared days, combined coverage and the gap between two inclusive date ranges.
Merge date ranges
Combine overlapping inclusive date ranges without double-counting covered days.
Shift a list of dates
Move dates by days or calendar months while preserving their input order.
Date format converter
Translate explicitly ordered numeric dates into unambiguous formats.
Add duration to a clock time
Add or subtract seconds and keep track of midnight crossings.
Merge clock-time intervals
Calculate distinct occupied time from overlapping same-day intervals.
Elapsed time between dated instants
Compare two ISO date-times with explicit UTC offsets.
Annual date planner
List the next occurrence of recurring month/day dates after a chosen reference date.
ISO week date to calendar date
Turn a week-year, ISO week and weekday into a Gregorian calendar date.
Julian date converter
Translate UTC calendar date-times and astronomical Julian dates.
Excel date serial converter
Translate date-times and spreadsheet serials while exposing the 1900 leap-day anomaly.
ISO day-time duration converter
Convert a fixed ISO-style day/time duration to seconds and back.
Calendar event file creator
Create a downloadable .ics file for one all-day or UTC-timed event.
12-hour & 24-hour time converter
Translate explicitly written AM/PM times and 24-hour clock times.
Add or subtract days
Move a calendar date forwards or backwards.
Day of the week
Find the weekday, day of the year and ISO week number.
Unix timestamp converter
Convert Unix seconds or milliseconds to a UTC date and back.
Age calculator
Calculate completed calendar years, months and days.
Weekday counter
Count Monday–Friday days between two dates.
Time duration calculator
Find elapsed time between two clock times.
Decimal hours converter
Convert decimal hours to hours:minutes:seconds and back.
Duration adder
Add a list of times, including negative durations.
Time zone viewer
See the same UTC instant in another time zone.