-=head2 Viewing Januari+Februari 2000 and 2001 together
-
-Define a graph area of 31+29 days (!) spanning Jan. and Feb.
- --start 20000101 --end 20000301
- DEF:jan2000=router.rrd:ds0:AVERAGE:start 20000101 end start+31d
- DEF:jan2001=router.rrd:ds0:AVERAGE:start 20010101 end start+31d
-Note: mind the extra day in 2000 ...
- DEF:feb2000=router.rrd:ds0:AVERAGE:start 20000201 end start+29d
-Note: 29 feb 2001 is *unknown*
- DEF:feb2001=router.rrd:ds0:AVERAGE:start 20010201 end start+28d
- VDEF:offset=jan2001,FIRST,jan2000,FIRST,-,-1,*
+=head2 Viewing the current and previous week together
+
+ --end now --start end-1w
+ DEF:thisweek=router.rrd:ds0:AVERAGE
+ DEF:lastweek=router.rrd:ds0:AVERAGE:end=now-1w:start=end-1w
+
+Shift the data forward by one week (604800 seconds)
+
+ SHIFT:lastweek:604800