Let's make GUI beautiful at last!
increase margins/spaces - at the moment all over UI feeling is "cramped"
avoid using CAPS! - it is less readable and wrong by sense (that is caps are to cry rather to say)
avoid too different font sizes - say, date and day of week can be the same size as task/event itself. We have other ways to mark day headers out. I guess slightly different background brightness is the less distracting. The same is applicable for the titles on right panel (calendars and so on managing).
avoid removing "just list" presentation mode on tablets - for portrait mode it would be very handy.