Skip to content
This page is also available in your language. Switch

Sync settings

Choose what your account keeps in step on every device where you are signed in.

  • My tools

    Always synced: the tools on your board, their order and size.

  • The windows open on your start page, including what you typed in them.

  • Every note in the notepad – on the notepad page, on your board and in windows.

  • Every list of website shortcuts – on the shortcuts page, on your board and in windows.

  • Every grid in the cover grid maker – on its page, on your board and in windows.

  • Every list of bookmarked organisations in the OIN lookup – on its page, on your board and in windows.

  • Keeps your pipeline and saved recipes on all your devices. Your files are never synced – only the steps and settings.

Turning something off removes it from your account straight away. Your devices keep their own copy.

Notifications

Tools that can tell you about something new while a Synsi tab is open, even when you are in another tab or app. Choose them for this browser.

This browser cannot show notifications from websites.
Notifications are blocked for this site. Allow them in your browser’s site settings (the icon left of the address), then switch them on here.

  • Says “New message” while a Synsi tab is open – never who wrote it or what.

Your choice is stored in this browser only. Notifications never show personal content such as a message or a number. They work while a Synsi tab is open; closed tabs get none.

Browse all tools →

Leap Year Calculator

Check whether a year is a leap year and see how many days it contains.

My tools →

Leap year

–

Days in year

–

Next leap year

–

Date and time results follow the Gregorian calendar and standard time-zone data. Working-day counts exclude weekends but do not automatically remove public holidays. Check local rules and daylight-saving transitions when timing is critical.

Runs in your browser – your data never leaves your device Also available via our free API

How to use the Leap Year Calculator

  1. 1 Enter the date, time or values you want to calculate.
  2. 2 Review the result and the assumptions shown with the calculator.

How this calculator works

A Gregorian year is a leap year if divisible by 4, except century years unless they are also divisible by 400.

Assumptions and limitations

This calculator uses the Gregorian calendar, including its century-year rule.

Frequently asked questions

How is the result calculated?

A Gregorian year is a leap year if divisible by 4, except century years unless they are also divisible by 400.

What should I keep in mind?

This calculator uses the Gregorian calendar, including its century-year rule.

Last updated: