Allow showing multiple timezones "columns" (Y axis time labels) in the margin of the week view's timetable
Google Calendar's labs has a pretty nifty feature where you can set, in the preferences, a "secondary timezone" (with custom label), allowing you to easily schedule events in two timezones at once (see attached screenshot). Would be pretty awesome to have that ability for 2 or 3 timezones (if set) at the same time.
Originally reported in GNOME Bugzilla #753135 by @jfft