EasilyDo does not allow you to add new calendar events within EasilyDo, but you can edit the calendar event. To do this, tap the event card from within your EasilyDo feed, then tap the blue 'View In Calendar' button at the bottom of the screen. From there, you can edit the event details.
With that said, you can add time- based reminders to EasilyDo. To do this, tap the bell icon on the top of the screen, then tap 'Add Reminder'