All calculators
Choose the calculator that matches your date or time question. Each tool is free, works in your browser, and is designed to give a clear result without an account.
Every tool on MyDayStamp, in one place.
Time Zone Converter
Convert a meeting time between cities — daylight saving handled automatically.
Age Calculator
Your exact age in years, months, days — and a few fun numbers to go with it.
Countdown Calculator
Count down to a wedding, trip, or any date that matters — and share it.
Days Between Dates
Find the exact number of days, weeks, or months between two dates.
Pregnancy Due Date
Estimate your due date and see how far along you are, week by week.
Add or Subtract Days
Add or subtract days, weeks, or months from any date.
Day of the Week Finder
Find out what day of the week any date falls on — past or future.
Anniversary Calculator
How many years, months, and days since your big day.
Retirement Date Calculator
Find your exact retirement date and how many working days are left.
Business Days Calculator
Count working days between two dates, weekends excluded.
Pet Age Calculator
Convert your dog's or cat's age into human years.
Holiday Countdown
Days until Christmas, Thanksgiving, Easter, and other holidays.
ISO Week Number
Find the official week number for any date.
Time Until Retirement
Years, months, and days remaining until your target retirement age.
Calculator directory notes
This index lists every public MyDayStamp tool. The English pages are the canonical versions. Language folders under /es/, /fr/, /de/, /it/, /pt/ and /ar/ follow the same filenames so a link can be translated without changing the structure.
Prefer the English page if you need the longest explanation. Translated pages keep the same calculator logic and add local language labels. Results still use the Gregorian calendar unless a page says otherwise.
When two tools look similar, open both examples before you reuse a number. “Days between” counts a span. “Age” reports completed years plus leftover months and days. “Add or subtract days” moves one date. Mixing those three is the usual source of off-by-one errors.