This is a false analogy. Currencies are volatile whereas timezones are static and rule based.

Converting timestamps between time zones is perfectly reversible while there is a loss of information when you convert a value to a new currency.

Timezones are not static, and actually change somewhat frequently. A program that converts any given future time to UTC risks becoming incorrect about when that time is due to political changes that affect the timezone the given future time was in.

> Converting timestamps between time zones is perfectly reversible while there is a loss of information when you convert a value to a new currency.

False. This scenario absolutely does happen:

    2027-03-08 11:00AM (Local) -> 2027-03-08 2:00PM (UTC)

    (tzdata version changes)

    2027-03-08 10:00AM (Local) <- 2027-03-08 2:00PM (UTC)