=head1 SYNOPSYS
-B<DEF>:I<vname>=I<RRD file>:I<ds name>:I<CF>[:step=I<step size>][:<time range>>]
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>]
B<VDEF>:I<vname>=I<RPN expression>
=head1 DEF
-B<DEF>:I<vname>=I<RRD file>:I<ds name>:I<CF>[:step=I<step size>][:<time range>>]
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>]
This command fetches data from an B<RRD> file. The virtual name
I<vname> can then be used throughout the rest of the script. By
at an appropriate resolution will be chosen. The resolution can
be overriden with the L<--step|rrdgraph/item_Time> option.
The resolution can again be overriden by specifying the B<step size>.
-I<Not yet implemented:> [ The time span of this data
-is the same as for the graph by default, you can override this by
-specifying the B<time range>. ]
+The time span of this data is the same as for the graph by default,
+you can override this by specifying B<start and end>. Remember to
+escape colons in the time specification!
If the resolution of the data is higher than the resolution of off
graph, the data will be further consolidated. This may result in
DEF:ds0=router.rrd:ds0:AVERAGE
DEF:ds0weekly=router.rrd:ds0:AVERAGE:step=7200
+ DEF:ds0weekly=router.rrd:ds0:AVERAGE:start=end-1h
+ DEF:ds0weekly=router.rrd:ds0:AVERAGE:start=11\:00:end=start+1h
=head1 VDEF