What matters is consistency and our time system has tons of crazy inconsistent shit in our. Everyone knows about leap years, but do you know about leap seconds? Imagine trying to write a function to convert unix time to a current date and suddenly all your times are a second off.
Just look at this insane bullshit nonsense. The added complexity of time zones and daylight saving time is nothing compared to simply supporting our time system.
We need to synchronize all computer times with that one clock that can stay accurate to within 1 second every 40 billion years.