AGE & DATE TOOLS 🧁
29 focused calculators for birthdays, date differences, milestones and life planning. Clear inputs, useful results and documented methods.
AGE TOOLS
AGE CALCULATOR ★ FLAGSHIP
Calculate completed years, months and days, elapsed time, the next birthday and dated milestones. The optional birthday scene does not affect the result.
HOW OLD WAS I
Your exact age on any date in history — with era context.
Open tool → two peopleAGE DIFFERENCE
Compare two birthdays with an exact calendar-age gap.
Open tool → 9 worldsAGE ON PLANETS
Compare your age using published planetary orbital periods.
Open tool → size-basedDOG AGE
Estimate human-equivalent age by size and life stage.
Open tool → life stagesCAT AGE
Convert cat age with the established 24+4 model.
Open tool →BIRTHDAY TOOLS
BIRTHDAY COUNTDOWN
Live d/h/m/s timer + circular year-progress ring.
Open tool → .ics exportNEXT BIRTHDAY FINDER
When, what weekday, what age — calendar file included.
Open tool → generatorBIRTHDAY WISHES
Editable messages by relationship, tone and length — save or share favorites.
Open tool → halfwayHALF BIRTHDAY
Your halfway-there celebration date, Feb 29 handled.
Open tool → once onlyGOLDEN BIRTHDAY
Age = birth date. One shot per lifetime. Find yours.
Open tool → guideBIRTHDAY TRADITIONS
20 ways the world celebrates — from cake smashing to ear pulls.
Read guide →DATE & TIME TOOLS
DATE DIFFERENCE
Compare two dates with elapsed, inclusive and weekday-only totals.
Open tool → add or subtractDAYS CALCULATOR
Add or subtract a number of days from any date.
Open tool → dual modeMONTHS CALCULATOR
Add months with month-end clamping or convert month units.
Open tool → leap-awareYEARS CALCULATOR
Add years & convert, with leap-day handling explained.
Open tool → presetsTIME UNTIL
Countdown to Christmas, summer, New Year — anything.
Open tool → 4/100/400 rulesLEAP YEAR CHECKER
Apply the Gregorian rules to one year or a selected range.
Open tool →LIFE & MILESTONES
LIFE STATS
Watch exact elapsed time and clearly labeled biological estimates update live.
Open tool → calendarAGE MILESTONES
Calculate round ages and elapsed-time milestones with exact dates.
Open tool → ⚠️ gentleLIFE EXPECTANCY
Compare age with a selected population-average scenario.
Open tool → by countryRETIREMENT
Estimate a retirement date by country and target age.
Open tool → gifts tableANNIVERSARY
Time together + the full 1–60 year gift tradition table.
Open tool → cohortGENERATION FINDER
Boomer to Gen Alpha — your cohort report, edge cases included.
Open tool →