Google Calendar

You can sync your Google Calendar with Calendar Clock. This will make sure that Calendar Clock is always in sync with your Google Calendar. Note that Calendar Clock can only read your events and cannot add its own events to your Google Calendar.

On your computer, open Google Calendar;
In the top right, click Settings->Settings;
On the left panel, under “Settings for my calendars,” click the name of the calendar you want to use;
Click Integrate calendar;
In the "Secret address in iCal format" section, copy the link;
Paste the link as into the "Sync with online calendar" field in your Calendar Clock preferences page;
Click the enter button on your phone's keyboard to save the settings.

iCloud Calendar

You can sync your iCloud Calendar with Calendar Clock. This will make sure that Calendar Clock is always in sync with your Google Calendar. Note that Calendar Clock can only read your events and cannot add its own events to your Google Calendar.

On your computer, open iCloud Calendar;
On the left panel, click the account icon of the calendar you want to share;
Select Public Calendar and copy the link;
Paste the link as into the "Sync with online calendar" field in your Calendar Clock preferences page;
Click the enter button on your phone's keyboard to save the settings.