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 →

Date & Time

Plan dates and convert times with clear calculators for everyday schedules, deadlines and time zones.

Age Calculator

Calculate your exact age in years, months and days, plus total weeks and days lived and the days until your next birthday. Free online age calculator.

Days Between Dates

Count the days between two dates, including weeks, months, years, hours and business days (Mon–Fri). Option to include the end date. Free calculator.

Week Number Calculator

Find the ISO 8601 week number for any date. See the week-year, weekday, and Monday-to-Sunday dates with this free week calculator.

Date Add or Subtract Calculator

Add or subtract a number of days, weeks, months or years from a date, with month-end dates handled safely.

Time Duration Calculator

Calculate the elapsed time between two clock times, including intervals that cross midnight.

Countdown Calculator

Count the days, full weeks and remaining days from a start date to a target date.

Time Zone Converter

Convert a local date and time between common IANA time zones and see the UTC offset and Unix timestamp.

Unix Timestamp Converter

Convert Unix timestamps in seconds or milliseconds to a readable UTC date and back again.

Leap Year Calculator

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

Calendar

Free online calendar: today’s date, ISO week number, day of the year and quarter, month and year views with week numbers, plus public holidays for 5 countries.

Popular presets

Date and time tools for everyday planning

Find the number of days between dates, count weekdays, calculate age, add or subtract calendar time, and check countdowns or ISO week numbers. Convert a local time between supported time zones, check leap years, measure a time duration or translate a Unix timestamp.

Date calculations follow the Gregorian calendar. Working-day estimates count Monday through Friday and do not automatically remove public holidays. Time-zone conversions use the selected IANA time zones; daylight-saving transitions can make some local times ambiguous or invalid, so double-check times near a clock change.