This calculator determines the duration between two dates: a "Date of Birth" and an "Age at Date" (which defaults to the current day but can be changed). The result is presented in a detailed format, including years, months, weeks, days, hours, minutes, and seconds.
We use the most common age calculation system, where age increments on the anniversary of the birth date. For instance, if someone is born on January 1st, 2000, they are considered 1 year old on January 1st, 2001.
This system is common in many Western cultures. It differs from other cultural systems, such as the traditional Chinese method where a baby is considered one year old at birth and gains another year at the start of the Lunar New Year.
Calculating months and days can sometimes be ambiguous, especially when dealing with end-of-month dates (e.g., February 28th to March 31st). Our calculator follows a consistent method: for example, February 20th to March 20th is considered one full month. Similarly, February 28th to March 28th is treated as one month, and we then account for the remaining days.