No, leap seconds are included in Unix time, so adding leap seconds won't change how it's converted into a human-readable date. To store it without leap seconds

No, leap seconds are included in Unix time, so adding leap seconds won't change how it's converted into a human-readable date. To store it without leap seconds you would use TAI time. Anyway, sure, for scheduling something in a calendar you would want something timezone-aware. But not for storing timestamps. If a country changes what time zone they used it the past (not sure why they would ever do that) that shouldn't move the time the objective time an event occurred at.