Add Days to Date

Add or subtract any number of days to a date. Handles month rollovers and leap years automatically. Instant, private, in your browser.

Age Calculator

Find your exact age in years, months and days from your date of birth. Instant, private — runs entirely in your browser.

Date Difference Calculator

Calculate how many days, weeks, months and years between two dates. Works instantly in your browser — no server, no data sent.

Time Zone Converter

Convert a UTC datetime to any IANA timezone (America/New_York, Europe/London, Asia/Tokyo…). Uses your browser's built-in Intl engine — no data sent anywhere.

Work Hours Calculator

Calculate total worked hours between a start and end time, with optional break deduction. Handles night shifts (crossing midnight). Private, instant, in your browser.