You can now sync with your calendar when setting up events.
Just export from your calendar application to the standard iCal format (.ics) and then upload this file under 'options' when creating your event. Alternatively, supply the URL of an online iCal file (see under 'settings' on Google Calendar, for example).
This works two ways. If you sync before you select any times, all your free time will turn green. If you begin by painting some proposed times and then sync, the selection will be trimmed according to your availability.
You can sync to a number of different calendars one after another - the grid will be left showing the common free time.
To avoid the copy-and-paste each time you specify an iCal URL, you can now store them on your account as a 'quick sync'. Choose a simple name for your calander and complete the form at the bottom of the 'your account' page. You get a link at the top of your event grid - sync with just a click.
Add as many calendars as you like and click in sequence to find the common free time between them.
You can now easily share an event's results page, even if it is attached to an account. Just click the checkbox at the bottom of the grid.
Tick and simply circulate the URL of the results page to allow your colleagues to see results. When unticked, you need to be logged in to your account to access the page.