If you're a moron, like me
One of the banes of my existence is managing the timezone thing - I live in mountain time and work largely with clients and employers who are based on the East Coast. Normally it's not that big a problem, except when I travel there. Flight times are always local time, so you get hosed when you take the flight info stuff from a travel booking site and put it in your calendar - yes it lands at 11:00 pm, but that's mountain, so like 1 am Eastern. I'm forever making the wrong calculations.
Because I am a moron.
But I just added the Mountain timezone to my Outlook display following these helpful instructions from Lifehack, and I'm feeling better already!