Relativity doesn't really come into it. Even at orbital altitudes, the difference due to dilation is miniscule. Places that need high quality time will use a lo

Relativity doesn't really come into it. Even at orbital altitudes, the difference due to dilation is miniscule. Places that need high quality time will use a local atomic clock disciplined by GPS, where GPS already factors in the dilation. This gives you very close to constant time across the earth's geoid. Variations due to temperature in your DC and many other factors will utterly swamp any time dilation differences in this context, and even without those the discipline would have no problem flattening it out.