Uptime +7 days Smart Group - need help with extension attribute?

I would consider doing some searches here for EAs related to getting the uptime of machines. There are many different approaches. It's possible the way your script is working is creating false positives. I'm not able to test it out right now, but I can take a look at it later to see. My guess is a different approach might give you better results.

Here's an example of getting the number of days uptime using sysctl, current unix time, and some math

#!/bin/bash

echo "<result>$(expr $(expr $(date +"%s") - $(sysctl kern.boottime | awk -F'[= |,]' '{print $6}')) / 60 / 60 / 24)</result>"

Here's my EA for uptime (I round to 1 day if it's been up less than that). Your IF statement looks whack, to use a technical term, I don't know what it's doing.

I'd probably write this differently nowadays, but it works.

#!/bin/bash

uptimeRes=$(uptime)
if [ "$(echo $uptimeRes | grep day)" ]; then
    uptimeDays=$(echo $uptimeRes | awk '{print $3}')
else
    uptimeDays=1
fi
echo "<result>$uptimeDays</result>"