[network-health] How is a relay's uptime determined?

Hello there, I run a tor middle relay, and last night I restarted the service due to an update. Then, looking up the relay in the Tor site, it looks like I lost all the uptime and flags. A bit annoying since I have had the server down for several minutes without consequences in other times. I was 5 days away from the t-shirt :( I was just wondering under what circumstances the relay's uptime is reset, if possible. Thanks.

-- arf20