Sync Your 3rd Party Calendar App With Trello
Using the Calendar Power-Up, Trello offers the ability to import your board calendar into most any calendar application via an iCal feed. However, some applications may not update this feed very frequently, causing information in the calendar to be out of date as soon as a change in Trello is made.
Using Cronofy to Instantly Sync Calendars with Trello
We recommend using a 3rd party tool called Trello Calendar Sync from Cronofy. It's a free tool that allows you to instantly synchronize one or many of your boards with a variety of calendar services. It even allows you to customize the calendar event durations.
Setup is a simple process of first linking your calendar service, then linking your Trello account. From there, choose the board or boards you would like to have calendar events for, set the event duration, and sync!