I'm adding this in case any one else finds this as I did. If you want to use this to modify the time range of a chart in a dashboard with a shared time picker then you have to deal with $time.latest$ will spit out "now" if the latest time is now, or epoch time if it's not. to get round this you can add something like this
eval earliest=if("$time.latest$" == "now","-2m",$time.latest$-120)
so I was wanting to limit this particular chart to the latest 2mins of the selected time range.
... View more