Fix aggregation time duration doc
@@ -1914,7 +1914,7 @@ The above syntax includes the following:
|`<input stream>` |The stream that feeds the aggregation. **Note! this stream should be <br/>already defined.**
|`group by <attribute name>` |The `group by` clause is optional. If it is included in a Siddhi application, aggregate values <br/> are calculated per each `group by` attribute. If it is not used, all the<br/> events are aggregated together.
|`by <timestamp attribute>` |This clause is optional. This defines the attribute that should be used as<br/> the timestamp. If this clause is not used, the event time is used by default.<br/> The timestamp could be given as either a `string` or a `long` value. If it is a `long` value,<br/> the unix timestamp in milliseconds is expected (e.g. `1496289950000`). If it is <br/>a `string` value, the supported formats are `<yyyy>-<MM>-<dd> <HH>:<mm>:<ss>` <br/>(if time is in GMT) and `<yyyy>-<MM>-<dd> <HH>:<mm>:<ss> <Z>` (if time is <br/>not in GMT), here the ISO 8601 UTC offset must be provided for `<Z>` .<br/>(e.g., `+05:30`, `-11:00`).
-|`<time periods>` |The time periods can be given as a range separated by three dots, or as comma separated values. A range would be given as sec...year, where aggregation would be done per second, minute, hour, day, month and year. Comma separated values can be given as min, hour. However, skipping durations is not yet supported for comma separated values (e.g min, day is not a valid clause since hour duration has been skipped)
+|`<time periods>` |Time periods can be specified as a range where the minimum and the maximum value are separated by three dots, or as comma-separated values. <br><br> e.g., A range can be specified as sec...year where aggregation is done per second, minute, hour, day, month and year. Comma-separated values can be specified as min, hour. <br><br> Skipping time durations (e.g., min, day where the hour duration is skipped) when specifying comma-separated values is supported only from v4.1.1 onwards
!!! Note
From V4.2.0 onwards, aggregation is carried out at calendar start times for each granularity with the GMT timezone
