rs.status() does not display information uptime of the server where it run.

For example :
PRIMARY>rs.status()
{
"set" : "shard4",
"date" : ISODate("2011-08-26T13:19:39Z"),
"myState" : 1,
"syncingTo" : "10.121.4.13:27024",
"members" : [
{
"_id" : 0,
"name" : "10.120.4.13:27024",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"optime" :

{ "t" : 1314364699000, "i" : 1 }

,
"optimeDate" : ISODate("2011-08-26T13:18:19Z"),
"self" : true
},
{
"_id" : 1,
"name" : "10.121.4.13:27024",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 79,
"optime" :

{ "t" : 1314364699000, "i" : 1 }

,
"optimeDate" : ISODate("2011-08-26T13:18:19Z"),
"lastHeartbeat" : ISODate("2011-08-26T13:19:37Z"),
"pingMs" : 70
},
{
"_id" : 3,
"name" : "10.120.4.14:29024",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 79,
"optime" :

{ "t" : 0, "i" : 0 }

,
"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
"lastHeartbeat" : ISODate("2011-08-26T13:19:38Z"),
"pingMs" : 0
}
],
"ok" : 1