Don't forget changing the day 1/3 of the time. But more importantly, if I'm scrambling to solve an incident, the last thing I want to do is deal with time conversions in my head.
You just do it once and think in UTC going forward. But as I said to the other person, if you're only dealing with one timezone it's fine, just when you have multiple it's a lot easier to just deal with one time and let everyone convert.
I'd expect everyone who works in computer related jobs to know their UTC offset.
