Date & Time Tools Tools

Free online date and time tools — a calendar-aware date difference calculator, computed entirely in your browser. No uploads, ever.

7 tools

Date Difference

Get the exact calendar difference between two dates in years, months and days, plus total days, weeks, hours and minutes.

Time Zone Converter

Convert any date and time across 40 IANA time zones simultaneously. DST handled automatically. Copy any result with one click. No server, no sign-up.

Date Add / Subtract

Add or subtract years, months, weeks, days, hours and minutes from any date. Month-end clamping, ISO week number and a copyable ISO 8601 stamp.

Countdown Timer

Live countdown to any date and time in days, hours, minutes and seconds. Shows total hours and minutes too. Past dates switch to elapsed time automatically.

Time Card Calculator

Calculate worked hours and overtime from clock-in, clock-out and break data. Supports night shifts, daily and weekly OT caps, and optional gross pay.

Also in Date & Time Tools

Tools from other categories tagged with Date & Time Tools

Age Calculator

Calculate your exact age in years, months, days, hours, and minutes from your date of birth. Shows total counts and next birthday countdown.

Daily Planner

Build a time-blocked day plan with a progress bar, sort by time, copy as plain text or download as Markdown. Saves to your browser per date — no account needed.

Why These Tools

Date Difference Calculator exists because dividing a day count by 30 and calling it months is wrong the moment a real month runs short or long, and most quick date-math answers make exactly that mistake. It counts real calendar months instead, checked against Python's dateutil library on five cases during development, including the leap-day edge case that trips up simpler implementations. Time Zone Converter handles the other half of the problem: a date and time that is clear in one city needs the right offset to mean anything elsewhere, and it shows up to 8 IANA zones simultaneously with DST abbreviations that update for the exact date you enter. Working-day counting and countdown timers are next in line.