Doodle offer various ways to connect calendars. You can create and participate in polls directly from your Doodle calendar view without needing to switch back and forth between your polls and your calendar.
Outlook.com and Office 365
Your Outlook.com and Office 365 calendars can be easily connected with a single click. Just go to Manage Account and open the Calendars section. Click the button 'Office 365 / Outlook.com' and log in using your account information. Then select ‘Yes’ in the pop-up window to give Doodle access to your calendar.
Other Outlook versions
All Outlook versions can be connected to Doodle using ICS feeds. Please read here how to connect Outlook via ICS feeds.
Others like Yahoo and many more
Many online calendars can be connected by using ICS feeds.