This is a follow-up question/request to Is there a way to know the new launched sites over the years? and is related to this Area 51 discussion: Tooltip showing date/time of site launch.
The All sites via of Stack Exchange gives tooltips for most of the raw variables shown, except for the site age.
Please add the site (launch) dates as a tooltip, similar to what is common for all dates on the site.
It will provide consistency associated with date references across the entire network.