It should phone the mothership dayly to check legislation changes. You go to work on Monday and when you open the program it shows a nasty messages that explain

It should phone the mothership dayly to check legislation changes. You go to work on Monday and when you open the program it shows a nasty messages that explains the change, disable the main button and ask for another $x to enable it again. Users will be angry. In serious countries, the changes will be anounced in advance, so the author will have to track all of them and may show a warning a few days/weeks before the deadline. But here in Argentina a few years ago we decided to skip DST one week before the change. I guess the mantainers of all OS still hate us.