With Problem Smart Group Using a 'Date' Result from Extension Attribute

Can we see an example of your output to make sure it's formatted correctly?

Hi,

thanks for your interest. Let's start with the EA, the relevant part is

...
if [ $isLocalIP -eq 1 ]; then date=$( date "+%Y-%m-%d %H:%M:%S" ) echo "<result>$date</result>"
fi

exit 0
...

On the JSS it looks like this: "LastTimeOnSite: 2017-03-24 11:31:21"

The DB gives me:
...
mysql> select report_id, value_on_client from extension_attribute_values where extension_attribute_id = 8;
--------------------------------
| report_id | value_on_client |
--------------------------------
| -1 | |
| 1780 | |
| 1805 | 2017-03-24 11:08:07 |
| 1809 | 2017-03-24 11:31:21 |
| 1808 | 2017-03-24 11:30:26 |
| 1806 | 2017-03-24 11:20:27 |
| 1804 | 2017-03-24 10:51:22 |
| 1807 | 2017-03-24 10:51:22 |
| 1781 | |
--------------------------------+
9 rows in set (0.00 sec)

mysql> ...

I assume it it something rather simple, but I don't spot it.

Hmm. Nothing looks wrong about your EA to me at first glance. The EA is saved as a Date Extension Attribute I assume, or else you wouldn't even be able to try creating a Smart Group based on a date value.
Can you give us an example of an advanced search or Smart Group criteria you're using that isn't populating anything?

Tes, the EA is saved with a Data Type of Date.

The smart group is very simple, there is just one single criterion: "LastTimeOnSite after 2017-01-01":

I also tried
- 'before' that date,
- before 2018-01-01
- less than x days ago, with x being 1 or 0
- more than x day ago, with x being 1 or 0

For all of these the smart group shows zero members.