Obviously it all depends on the application: Birthdays (as the article mentioned) are not points in time and mean different things depending on where you are,

Obviously it all depends on the application: Birthdays (as the article mentioned) are not points in time and mean different things depending on where you are, so best stored as a year-month-day combo without any zone information. Past times are not that big of an issue actually, just use UTC and convert to local time to display, but calendars schedule for the future, and you can't always calculate a future time in UTC. In e.g. distributed system where monotony and ordering is important UT1 would actually be even better than UTC, as UTC has occasional jumps (hence the workarounds, like googles skewed NTP)