5 calculators
Everyday Life Calculators
A small section for the arithmetic of dates. It covers how old someone is on a given day, when a birthday next falls and on which weekday, the gap between two dates, and how long remains until something you are counting down to.
Age, or the gap between two dates
The age calculator answers how much time has passed since a date, given in years, months and days, and handles the awkward cases such as a February 29 birthday. The date calculator answers the more general question of the distance between any two dates, or what date falls a given number of days from another. If the question involves a person, the age tool is usually the one; if it involves a deadline, the date tool is.
- Age Calculator
- for exact age in years, months and days on any date, leap days included.
- Date Calculator
- for the span between two dates, or a date a set number of days away.
- Birthday Calculator
- for the next birthday, the weekday it lands on, and the traditions attached to the date.
Where these calculations go wrong
- Months are not a fixed length
- Adding one month to January 31 has no obvious answer, and different systems resolve it differently. Age in years, months and days depends on that choice, which is why an age given in months can disagree slightly between tools that each did something defensible.
Popular Everyday Life calculators
Everyday Life
Birthday Calculator
Find your next birthday, the weekday it falls on, and how many days are left, plus your current age, decimal age, next ten birthdays, and half birthday.
Everyday Life
Age Calculator
Find a completed age in years, months and days on any date, with total calendar days, weeks, and a next birthday countdown. Also gives the date you reach a milestone age.
Everyday Life
Age Difference Calculator
Find the exact age gap between two people in years, months, and days. Works for couples, siblings, parents-children, or any two people.
Everyday Life
Date Calculator
Calculate days between dates, add or subtract days from a date, count business days, and find days from today. Works as a date calculator, date duration calculator, days between dates calculator, add days calculator, subtract days calculator, business days calculator, calendar calculator, countdown calculator, and weekday calculator.
Everyday Life
Days Until Date Countdown
Calculate exactly how many days, weeks, hours, and seconds are left until any custom date, birthday, or anniversary.
Birthdays & Age
3 calculatorsEveryday Life
Age Difference Calculator
Find the exact age gap between two people in years, months, and days. Works for couples, siblings, parents-children, or any two people.
Everyday Life
Birthday Calculator
Find your next birthday, the weekday it falls on, and how many days are left, plus your current age, decimal age, next ten birthdays, and half birthday.
Everyday Life
Age Calculator
Find a completed age in years, months and days on any date, with total calendar days, weeks, and a next birthday countdown. Also gives the date you reach a milestone age.
Dates & Countdowns
2 calculatorsEveryday Life
Date Calculator
Calculate days between dates, add or subtract days from a date, count business days, and find days from today. Works as a date calculator, date duration calculator, days between dates calculator, add days calculator, subtract days calculator, business days calculator, calendar calculator, countdown calculator, and weekday calculator.
Everyday Life
Days Until Date Countdown
Calculate exactly how many days, weeks, hours, and seconds are left until any custom date, birthday, or anniversary.
Related sections
- Education for the wider date and time arithmetic, worked through with the formulas shown.