When creating a stock or trend chart data attachment, you must identify the variable or field to use as the timestamp. You can use either a DataView field or apama.timestamp. When a variable or field changes, the correlator generates an Update event with the new value. The timestamp in the Update event will be used by the dashboard as the time that the change occurred and used to chart the value.

The default timestamp is apama.timestamp. It corresponds to the timestamp the correlator adds to an Update event when the event is generated. This timestamp is suitable in most cases and is always available.

If you want greater control over the value of timestamps, specify a DataView field as the timestamp. Within your DataView, you will need to set the value of the timestamp variable or field when changing the value of any other variable or field. Do this if you want use timestamps from an external event feed such as market data.

Only number variables can be used as timestamps. Timestamps need to be in UTC format where the value represents the number of seconds since the epoch, January 1, 1970. The TimeFormatPlugin can be used to convert string values to UTC format.