add blob to basics documentation about negative shift
@@ -204,6 +204,11 @@ The same works for range vectors. This returns the 5-minute rate that
rate(http_requests_total[5m] offset 1w)
+For comparisons with temporal shifts forward and backward, a negative offset
+can be specified:
+
+ rate(http_requests_total[5m] offset -1w)
+
### @ modifier
The `@` modifier allows changing the evaluation time for individual instant
