How Long Ago Was June 29 2025. To calculate the number of years between two dates in decimal form, first, find the number of days between the dates. Subtract the start date from the end date based on the formula.
It’s a free tool that computes the duration between two dates in years, months, and days. This free age calculator computes age in terms of years, months, weeks, days, hours, minutes, and seconds, given a date of birth.