As-Of Date display:
This option controls if, and how the latest query time is displayed in the top right hand side of the panel.
Depending on the data source and query, each row in Multistat may be updated at different times.
This display can be useful in showing the latest timestamp of all the data displayed in the panel - as a snapshot date/time.

Date display formatting string uses common standards. (see here)

Setting the format string to the reserved keyword "ELAPSED" displays the time as the elapsed time since the last data update (as per the latest grafana refresh operation).