[Doc]Not support "M" time unit in offset param
@@ -238,7 +238,7 @@ happens.
The `offset` parameter is used to change the start value of each bucket by the
specified positive (`+`) or negative offset (`-`) duration, such as `1h` for
-an hour, or `1M` for a month. See <<time-units>> for more possible time
+an hour, or `1d` for a day. See <<time-units>> for more possible time
duration options.
For instance, when using an interval of `day`, each bucket runs from midnight
