> And if some legislature somewhere on earth makes a surprising change to their DST rules, we can identify all of the events that are affected by that change and update that denormalized UTC time accordingly.
And how do we automate getting to know about, and performing, those updates in our application databases? If that is not easily automatable, I think storing the UTC time as well will cause problems.
I suggest storing a "denormalized UTC time", a calculated column would work fine for that.
For automation: install the latest tz database (I use pytz for this, usually) and then run a batch job to see what's changed. Not trivial but not impossible either. Running events websites is hard!
And how do we automate getting to know about, and performing, those updates in our application databases? If that is not easily automatable, I think storing the UTC time as well will cause problems.
Maybe the UTC time should be a calculated column?