> How so? 2030-07-01T18:00:00+01:00 is a well-defined point in time, is it not? It may or may not be local time in London, but it's unambiguous. Being unambigu

> How so? 2030-07-01T18:00:00+01:00 is a well-defined point in time, is it not? It may or may not be local time in London, but it's unambiguous. Being unambiguous isn't helpful if it is wrong. It is a very common desire to want to set a meeting based on the local time of a destination. The only future-proof way to store such a time, is to remember the destination and the desired local time. This is the only way the proper moment can be calculated and kept in sync with reality. The unfortunate fact is, the local time could be altered by decree, in any number of ways, in the interim timespan between setting a reminder, and when it happens.