Arguably refresh_date should be set to 'now' at this point but this doesn't change anything and that logic might be teased out more when we turn out eyes to the rebuild scripts
<name>cache_date</name>
<type>timestamp</type>
<title>Group Cache Date</title>
+ <required>false</required>
<comment>Date when we created the cache for a smart group</comment>
<add>2.1</add>
</field>
<name>refresh_date</name>
<type>timestamp</type>
<title>Next Group Refresh Time</title>
+ <required>false</required>
<comment>Date and time when we need to refresh the cache next.</comment>
<add>4.3</add>
</field>