relative times in the IDV; time loops

Geophysical mantle models have time steps in millions of years, and are not 
tied to
current clock time, of course.

If you have a netCDF file with data time value and unit such as "250 Myear" the data appears in the IDV but the time label is something like "250001794-10-20 07:29:59Z"

If you do a time animation loop of two or more of these, from one data file per time step, separated by say 50 million years, the odd times do loop in the label, but all displays appear all the time.

Is there some way to not tie the time to the time at the moment, just show "250 Myr," and to make the loop work for each data time in separate files?

Stuart Wier