About DateKit

DateKit is a small set of free calculators for everyday date math: your exact age, the gap between two dates, countdowns, and week or day-of-year lookups. Every tool runs in your browser, so the dates you type never leave your device.

We built DateKit because date arithmetic is full of edge cases — leap years, month lengths, weekends — that are easy to get wrong by hand. Our tools follow the standard Gregorian calendar so the result is the one you would get from a calendar on the wall.

DateKit is not an official records system. For legal, payroll, or government purposes, always use the document or system your authority requires.