I am using the rest services within the search to get information on alerts that have triggered. I am trying to piece together alert information and can find most of it. What I am unable to find; maybe not knowing all the fields, is the trigger time. I see that fired_alerts has the next_scheduled_time but I don't see that it has the triggered time. I do not have access to _index so I am working on getting some of this information here if possible.
The unintuitive place to find that is in the triggered_alert_count field in | rest /services/saved/searches
This tells the count for the alert but not the time.
Sorry for providing the wrong information.
The trigger_time field is not returned as part of the general alerts/fired-alerts query. You get it only when you request information about a specific alert name.