Across

Keeps your calendars in step, across Google Calendar, Apple iCloud Calendar and calendar subscriptions.

Across is an independent, non-commercial service run by an individual developer. Signing in is limited to invited accounts, and the app itself is not open to the public. This page describes what Across does and how it uses your data. See also the privacy policy.

What Across does

Calendar sync

Copies events from calendars you choose into a target calendar you choose. About every 5 minutes (every 30 minutes for calendar subscriptions) it checks for changes and updates or removes its copies. By default it covers events from 2 weeks ago to 6 months ahead, copies each occurrence of a repeating event separately, and skips events you declined.

You pick the detail

Every copy has the original's time. It shows only "Busy", the title, or the title with the description (up to 2,000 characters by default) and, if you choose, the location. On Google Calendar, copies are private by default. Guests, organizers, video-call links and reminders are never copied, and no invitations are sent.

Works across providers

Google Calendar, Apple iCloud Calendar and read-only calendar subscriptions (ICS links). Copies can go from one provider to another, for example from Google Calendar into iCloud Calendar.

See it all together

View up to 12 of your calendars side by side for up to a week, see the history of every sync, and look up why an event was or was not copied.

Your day and your week

Summaries of booked time, free time and overlaps for the calendars you pick (every calendar Across can read, until you pick), plus an image of your day and your week. The images are refreshed about every 15 minutes and can be fetched from a separate address with a private access key; anyone who has the key can view them. They show busy times coloured by calendar, and event titles only for calendars that allow titles. Titles are allowed by default for a calendar you pick, and you can turn this off per calendar.

Safe by design

Across writes only to calendars it created or that you explicitly allowed as targets. In those calendars it creates, updates and deletes only the copies it made. When you ask, it also changes a calendar's colour or deletes a calendar Across created. New sync rules start as a preview that you approve before anything is written, and unusually large changes wait for your approval.

Clean up at any time

The cleanup page removes the copies Across made for a rule or a target calendar once you confirm how many. Deleting a rule goes through this step. Copies Across no longer manages, for example because guests were added, are never deleted automatically and are listed for you. Your original events are never modified or deleted.

Why Across asks for access to your Google account

Across requests only the Google permissions its features need. Signing in asks only for your email address and Google account ID. When you connect a Google account, you choose one of two sets of permissions, and Google asks for exactly that set:

Personal connection: sign-in, your calendar list, and calendars Across creates. Across can list your calendars and create its own calendars. It can read, create, change and delete events only in calendars that Across created. It cannot read or change events in your other calendars.
Work connection: sign-in, your calendar list, viewing events, and changing events on calendars you own. Across reads events in the calendars you use it with, and writes copies only into calendars you own and have allowed as targets. It never changes events it did not create. This connection cannot create calendars.

Associate you with your personal info on Google · See your primary Google Account email address openid, email

Sign-in and both connections. To identify you, check that your account is invited, and keep connected accounts apart.

See the list of Google calendars you're subscribed to https://www.googleapis.com/auth/calendar.calendarlist.readonly

Both connections. To list your calendars (name, colour, time zone and your access level) so you can pick sources, targets and summary calendars.

Make secondary Google calendars, and see, create, change, and delete events on them https://www.googleapis.com/auth/calendar.app.created

Personal connection. To create a separate calendar for copies when you ask for one, keep the copies in it up to date, include it in your summaries, change its colour, and delete it when you ask.

View events on all your calendars https://www.googleapis.com/auth/calendar.events.readonly

Work connection. To read the events in the calendars used by your sync rules, your day and week summaries (every readable calendar until you pick), the side-by-side calendar view and the "why was this not copied" lookup.

See, create, change, and delete events on Google calendars you own https://www.googleapis.com/auth/calendar.events.owned

Work connection. To create, update and delete the copies Across makes, only in calendars you own and have allowed as targets. Across does not change events it did not create.

How this data is used

Your Google data is used only to provide the features described on this page, for you.
It is not sold and not used for advertising.
It is shared only as needed to provide Across: copies of events are written to the target calendars you chose, which can be at another provider (for example Google Calendar events copied into Apple iCloud Calendar); day and week images can be fetched by anyone who has their access key, and include event titles only where titles are allowed; providers that host and deliver the service process it on the operator's behalf; and where the law requires it.
Google refresh tokens are stored encrypted (AES-256-GCM); short-lived access tokens are kept in memory only. You can revoke Across's access at any time in your Google Account settings. Removing an account in Across deletes its stored credentials and asks Google to revoke Across's access.

Across's use and transfer of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements. The use of information received from Google Workspace APIs, including Google Calendar, will adhere to the Google Workspace API User Data and Developer Policy. Data obtained through Google Workspace APIs is not used to develop, improve, or train generalized or non-personalized AI and/or ML models.

Read the full privacy policy and the terms of service.