Storing UTC is not a silver bullet

So the schema would have:

So our original entry is:

On March 14th 2020, when the time zone database 2020c is released, this is modified to:

This is the same as option 2: after the update, there’s a jump of an hour, but when it reaches 0, the conference starts. The UTC value is derived from that “golden” information, but can be re-derived if the context changes – such as when time zone rules change. We need to store information to tell us all the context about how we derived it (the old time zone rules version) and when updating the entry, we need to get back to the original information before we can re-derive the UTC instant using the new rules.

Source: codeblog.jonskeet.uk