It is in fact best to store the local time and the location (i.e., not "+01:00", but for example "Europe/Amsterdam"). Not UTC with or without time zone. For example, if you have an appointment in the future, and the time zone or daylight savings time rules change, this is the only way that the appointment can still be at the correct moment. And time zone rules do change.
And this way you can still represent absolute UTC time if you wish. With another representation, you cannot represent human-society time, which is often what you actually want.