Hi Julien You can use the RETURN= syntax. The backquotes evaluate the RETURN expression. Say you have a variable, called myvar, and you want the date string at L=12. You choose one point, and the tstart gives you the date at that index (tend would do the same, since it is just one point). yes? let dstring = "`t[gt=myvar,L=12], return=tstart`" This idea is used at the end of the FAQ, How can I label dates along a trackline? http://www.ferret.noaa.gov/Ferret/FAQ/custom_labels/label_dates.html Julien Demaria wrote: Hi, |