Task Manager can display events from your Google Calendar in its own Calendar and sync them both ways: changes made in Google appear automatically in Task Manager every few minutes, while changes made in Task Manager are saved to Google immediately. Google events are visible only to you - the connection is personal, just like your mailbox.

You can connect several accounts at once - for example, your company calendar and your personal one. Each connection has its own calendar and works independently.

This guide has three parts:

  • Part A - for the administrator, completed once: creating a “pass” in Google (without it, no one can connect an account).
  • Part B - for each user: how to connect your Google account.
  • Part C - optional: connecting a personal calendar with your own “pass” (only needed in special cases).

Part A (administrator, completed once): a pass in Google

Google requires every application connecting to a calendar to have its own “pass” - known as OAuth credentials (two long strings: a Client ID and Client Secret). You create them once, free of charge, in the Google Cloud console. It takes about 10 minutes. Follow these steps:

Step 1. Create a project

  1. Go to console.cloud.google.com and sign in with a Google account (preferably your company account).
  2. At the top of the page, click the project list and select New project (New project).
  3. Name it, for example, Task Manager, click Create (Create) and wait a moment for Google to set it up. Make sure it is selected (its name should be visible at the top).

Step 2. Enable the Google Calendar API

  1. From the menu on the left, select APIs & Services → Library (APIs & Services → Library).
  2. Enter Google Calendar API in the search box, click the result, then click Enable (Enable).

Step 3. Configure the consent screen

This is the window users will see when connecting their account (“Application X is requesting access to your calendar”).

  1. From the menu on the left, select APIs & Services → OAuth consent screen (OAuth consent screen). In the newer version of the console, this section is called Google Auth Platform (Google Auth Platform) - if so, click Get started (Get started).
  2. Enter the application name (for example, Task Manager) and your contact email address.
  3. Recipient type (User type / Audience):
    • Internal - only if the company uses Google Workspace. The most convenient option: no warnings, but only accounts from the company's domain can connect (a personal Gmail account won't connect - see Part C).
    • External (External) - use this in every other case. It works with any Google account.
  4. Save / Create.
  5. Important for the External type: in the Audience section (Audience), click Publish app (Publish app) so that the status changes from “Testing” to “In production” (In production). In testing mode, Google disconnects everyone every 7 days, so they have to reconnect.

Step 4. Create an OAuth client (the actual pass)

  1. From the menu on the left, select APIs & Services → Credentials (Credentials) - or Clients (Clients) in the new console.
  2. Click Create credentials → OAuth client ID (Create credentials → OAuth client ID).
  3. Application type: Web application (Web application).
  4. Name: for example, Task Manager.
  5. Now for the most important field: Authorised redirect URIs (Authorized redirect URIs). Click Add URI and paste EXACTLY the address shown by Task Manager under Settings → Advanced → Google Calendar (OAuth) - it ends with /api/gcal/oauth-callback.
    • Note: do NOT paste this address into the "Authorised JavaScript origins" field - that's a different field, and it will show an error. Leave it empty.
  6. Click Create. Google will display the Client ID (Client ID, ending in .apps.googleusercontent.com) and Client Secret (Client Secret, beginning with GOCSPX-). Copy both.

Step 5. Paste the pass into Task Manager

  1. In Task Manager, open Settings → Advanced → Google Calendar (OAuth).
  2. Paste the Client ID and Client Secret, then click Save.

Done - every user can now connect their account (Part B).

With the External type, Google will display a one-off warning when connecting: “Google hasn’t verified this app”. This is normal for company applications - click Advanced (Advanced), then Go to: <name> (Go to...). The limit for an unverified application is 100 connected accounts.

Part B (each user): connect your account

  1. Open Settings → Profile → Google Calendar.
  2. Click Connect Google account.
  3. Google will ask which account you want to sign in to - select the one whose calendar you want to see (company or personal).
  4. If the warning “Google hasn’t verified this app” appears, click Advanced, then Go to (this is a one-off step; see Part A).
  5. Allow access to the calendar (Allow / Allow).
  6. You will return to Task Manager. Open Settings → Profile → Google Calendar again - a list of your calendars will appear next to the connected account.
  7. Select a calendar and click Import. After a moment, its events will appear in the Task Manager Calendar.

Want to add another calendar, such as your personal one? Return to the same section and click Connect Google account again - this time, sign in to the other account. Each connection appears as a separate card in the list, with its own calendar and Disconnect button.

The import covers a period from 30 days in the past to one year in the future - you can change it using the “Window” fields for each connection.

Part C (advanced): connecting a personal calendar with your own pass

When is this needed? Mainly when the company pass is set to Internal (Internal) - Google will then prevent you from connecting your personal Gmail account. In this case, you can create your own pass using your personal Google account and connect with it:

  1. Complete all of Part A using your personal Google account (your own project, External type, publication, and your own Client ID and Secret). In step 4.5, paste the redirect address shown in the section below.
  2. In Task Manager, open Settings → Profile → Google Calendar and expand Connect with your own credentials (advanced).
  3. There you will find the redirect address (for step 4.5) and the Client ID and Client Secret fields - paste your credentials and click Connect with your own credentials.
  4. Then proceed as in Part B: sign in, grant consent, select a calendar and click Import.

Your credentials are stored in encrypted form and used only for this one connection. The administrator does not need to do anything.

How Google events work in Task Manager

  • In the Calendar, they use colours from Google: the colour assigned to the event or, if none is assigned, the colour of the selected calendar (very light colours are slightly darkened for readability). Events sent from Task Manager to Google are assigned the closest colour from the Google palette - the colours are approximate because the two applications use different palettes. When you click an event, the editing window clearly identifies it as a “Google event” and includes a link to open it in Google.
  • You can edit them just like any other event: drag them to another date or time, change their times and content, or delete them. Every such change is also saved to Google Calendar - and changes made in Google are automatically imported into Task Manager every few minutes.
  • Don't want to wait? Click the synchronisation icon (two arrows in a circle) in the top bar of the Calendar window. It only appears when Google Calendar is connected and downloads changes immediately - useful when you've just moved something in Google and want to see it in Task Manager straight away. Once complete, a message tells you how many events were added, changed and removed. The same button (“Synchronise now”) appears next to the connection under Settings → Profile → Google Calendar.
  • If the last automatic synchronisation failed, the icon turns orange, and hovering over it shows the reason. Click it to try again.
  • New events created in Task Manager are also sent to Google: selecting a calendar enables the “Add new Task Manager events to this calendar” option (shown next to the connection in Settings). Enabling it also immediately sends any future events that have not yet been exported. If you have multiple connections, events are exported to one selected calendar - selecting a calendar on another account switches the destination. An exported event retains its colour and continues to synchronise both ways (deleting it in Google will also delete it from Task Manager).
  • Deleting an event also deletes it from Google (the edit window makes this clear); “Undo” in the bar restores the event in both places.
  • Clicking opens the standard edit window with an open in Google link.
  • Future events send reminders just like regular Task Manager events (a notification at the start time); past events are added silently to the day's history.
  • All-day events are shown from 8:00 (multi-day events - until 18:00 on the final day) and remain all-day events in Google when moved to another day.
  • Disconnect (next to a specific connection) removes events imported from that account from your calendar - nothing is deleted from Google. Other connections continue to work.

Deleting Google account data

  • Disconnecting one account: Settings → Profile → Google Calendar → Disconnect next to the selected connection. The tokens and events imported into your calendar are removed (nothing changes in Google); other connections continue to work.
  • Deleting instance credentials (administrator): Settings → Advanced → Google Calendar (OAuth) → Delete credentials. This deletes the Client ID and Client Secret and disconnects all users connected through these credentials (their imported events disappear from Task Manager; nothing changes in Google). Connections using their own credentials (Part C) remain unaffected.
  • You can also revoke the application's access to your Google account at any time in Google: myaccount.google.com → Security → Third-party apps and services.

Troubleshooting

  • “The administrator has not configured the credentials yet” - Part A has not been completed (or you can use your own credentials - Part C).
  • Google says “You don't have access” when using a personal account - the company access pass is set to Internal; use Part C.
  • “Reconnect your account” error - Google has revoked access (for example, because the password was changed, consent was withdrawn in the Google account or the application was left in testing mode - see Part A, step 3.5). Disconnect the account and connect it again.
  • “redirect_uri_mismatch” error when connecting - the redirect URI in Google Cloud differs from the one shown by Task Manager (Part A, step 4.5). Correct it in Google Cloud (Credentials → Your OAuth client).
  • Synchronisation takes place whenever anyone is using the application (via the built-in scheduler); after a longer break, the first sync will run shortly after the application is opened.
  • A change from Google hasn't appeared after a few minutes? Click the synchronisation icon in the Calendar bar - you'll see either the number of changes downloaded or the specific reason for the failure. The status of the last run (date and any error) is also shown under Settings → Profile → Google Calendar.