It turns out NTP, the service that keeps our Unix boxes synced with international time servers, is lazy on the client side.
At Pivotal, our Macs sync up to time.apple.com to accurately reflect the time. This server isn’t lazy and will give back the current time when queried.
However, the NTP client-side daemon on our Macs has drifted as far off as 30 seconds because it isn’t actively polling time.apple.com. This can lead to strange errors (like longer download times than usual from certain servers). The simple fix is to reconnect to time.apple.com, or the NTP server of your choice.