Work out ages, durations, dates and deadlines without doing calendar maths in your head. These tools run entirely in your browser, so the dates you enter — birthdays, deadlines, anniversaries — never leave your device. The first live tool is the Age Calculator, which gives an exact age in years, months and days from a date of birth, handling leap years correctly, plus total days lived, the day of the week you were born, and your next birthday. Later batches add a date duration calculator, a countdown timer, a business-days calculator, a time-zone converter, a week-number finder and a Unix timestamp converter. Everything is free with no sign-up, and the tools work offline once the page has loaded — useful when you are planning around dates with no signal, or checking a deadline quickly on your phone. The tools also handle the awkward cases properly — leap years, month-end borrowing and dates far in the past — instead of approximating with 365-day years. Results are shown plainly, with the working visible so you can trust the answer.

1 tool live now. Use one below — the rest of this category arrives in later batches.

Live tools

• Age Calculator

  Age Calculator — runs entirely offline.

  Open tool →

Tools planned for this category

• Add/Subtract Days to Date

  Add/Subtract Days to Date — runs entirely offline.

• Alarm Clock (Browser)

  Alarm Clock (Browser) — runs entirely offline.

• Anniversary Calculator

  Anniversary Calculator — runs entirely offline.

• Birthday Day Finder

  Birthday Day Finder — runs entirely offline.

• Business Days Calculator

  Business Days Calculator — runs entirely offline.

• Chinese Zodiac Finder

  Chinese Zodiac Finder — runs entirely offline.

• Countdown Timer

  Countdown Timer — runs entirely offline.

• Date Difference Calculator

  Date Difference Calculator — runs entirely offline.

• Day Length Calculator

  Day Length Calculator — runs entirely offline.

• Day of the Week Finder

  Day of the Week Finder — runs entirely offline.

• Days Until Birthday

  Days Until Birthday — runs entirely offline.

• Decimal Hours to Hours:Minutes

  Decimal Hours to Hours:Minutes — runs entirely offline.

• Event Countdown (Shareable)

  Event Countdown (Shareable) — runs entirely offline.

• Golden Hour Calculator

  Golden Hour Calculator — runs entirely offline.

• Hours Calculator (Time Card)

  Hours Calculator (Time Card) — runs entirely offline.

• Hours Until Calculator

  Hours Until Calculator — runs entirely offline.

• Julian Date Converter

  Julian Date Converter — runs entirely offline.

• Leap Year Checker

  Leap Year Checker — runs entirely offline.

• Meeting Planner (Multiple Time Zones)

  Meeting Planner (Multiple Time Zones) — runs entirely offline.

• Military Time Converter

  Military Time Converter — runs entirely offline.

• Moon Phase Calendar

  Moon Phase Calendar — runs entirely offline.

• Online Timer

  Online Timer — runs entirely offline.

• Pomodoro Timer

  Pomodoro Timer — runs entirely offline.

• Printable Calendar Generator

  Printable Calendar Generator — runs entirely offline.

• Retirement Date Calculator

  Retirement Date Calculator — runs entirely offline.

• Shift Schedule Planner

  Shift Schedule Planner — runs entirely offline.

• Stopwatch

  Stopwatch — runs entirely offline.

• Sunrise & Sunset Calculator

  Sunrise & Sunset Calculator — runs entirely offline.

• Time Card / Timesheet Calculator

  Time Card / Timesheet Calculator — runs entirely offline.

• Time Duration Calculator

  Time Duration Calculator — runs entirely offline.

• Time Zone Converter

  Time Zone Converter — runs entirely offline.

• Week Number Calculator

  Week Number Calculator — runs entirely offline.

• World Clock

  World Clock — runs entirely offline.

• Zodiac Sign Finder

  Zodiac Sign Finder — runs entirely offline.

About this category

When will these tools be ready to use?

Tools are published in batches, starting with the 40 highest-value tools in Phase 1. Each tool goes live only when it is fully working, tested on mobile, and has its own written guide.

Will my files be uploaded when I use a tool?

No. Every Toolsvine tool runs 100% in your browser. Files, text and images you use in a tool never leave your device.