uptime of tor servers with dynamic ip after every ip change zero

[Arichy]

Hi,

is it right that the uptime of tor server gets zero when it's ip
changes? That would have some logic, true. But on the other way such a
tor server itself maybe runs some weeks without interruption, though.
Is that considered when assuming a tor servers availability in the tor
network? 
Maybe it would not be so good, when a tor server starts at
zero availability assumption every 24h because of ip change?

Greets, Arichy