The weekend before last, the last weekend in march was not the end of daylight savings, last weekend was. Why? because all the eastern states (SA, TAS, VIC, ACT, NSW) had finally agreed a new common daylight savings regime of first weekend in October to first weekend in April.
This did kind of leave WA, who were a year into their daylight savings trial using the old NSW last weekend in October to last weekend in March kind of in the lurch, but if the decide to go permanently for daylight savings they can change their enabling legislation appropriately.
Anyway this meant a festival of patching around Easter to make sure that servers were updated. And on the whole, most vendors provided patches or update tools that worked. Microsoft, typically wanted to charge $4000 for a Windows 2000 patch on the grounds that the OS was no longer on the supported list, when it took all of 15 minutes to script the registry change, but that's life.
Noting changed on the 'wrong' weekend and everything changed on the 'right' weekend.
Except for people's calendars on smart phones- some phone companies even stuffed up the timezone change- and people using hosted calendars such a google calendar which, being hosted overseas, hadn't caught up with all our changes.
However, not many dead, advance publicity about potential calendar problems got rid of most of the problems, and warned people to double check.
The message however to take away is not how well we did patching things, but just how prevalent the need to patch things was, and consequently the need for legislators to be aware of the need to get these changes in place in plenty of time and to avoid making ad hoc last minute changes the way they did for the Commonwealth Games or the Sydney Olympics.
These changes cost, time money and people. The update strategies need to be planned and tested.
As it was it wasn't the obvious things but things like car park machines, which these days are basically small networked computers, and building management systems that caused the problems, not the computers on desks and in data centres. This stuff is pervasive, and any change is automatically a big change ...