for a newly established relay - just 12 days old - with 2 outages during that time I'm wondering why the monthly value (~95%) is bigger than the value calculated over the last week (~92%)
Yup, this is a bug in Globe. When it calculates mean uptime it doesn't distinguish between 0 ("node is down") and null ("no data about uptime or downtime"). Here's what Onionoo returns for this relay's uptime in the past week:
Globe tells me mean uptime is 98.82%. That's 167 times value 999 times factor 0.001001001001001001 divided by 169 values.
What it should calculate is 167 times value 999 times factor 0.001001001001001001 divided by 167 values, which is 100%.
By the way, there's a related bug in the graphs which shouldn't drop to zero in case of null values but which should stop drawing the line and resume drawing at the next non-null value.
cumulative 50 down hours in last 30 days, one-month
up-time show as 93.31% where it actually is 93.06%
The 0.25% error is large enough to cause one to beleive
that the Guard flag will return several days before
it actually will.
A nice enhancement would be to show an accurate
rendering of the dir-auth calculation of weighted
up-time alongside the unweighted value so one can
better see how far away from receiving the Guard
and Stable flags a particular relay is.