I tried using |rest command but was unsuccessful in finding last trigger time, alert creation date fields in that. Please help.
This search should have most of the details you want.
| rest /services/saved/searches
You'll have to join it to the _audit index to find out when they were created though
Check monitoring triggered alerts http://docs.splunk.com/Documentation/Splunk/6.6.2/Alert/Triggeredalertaction
http://docs.splunk.com/Documentation/Splunk/6.6.2/Alert/Reviewtriggeredalerts
Splunk's built in views should provide some guidance or may achieve what u need.
Also alert manager likely has some nice views once you get deeper into alerting and workflow
https://splunkbase.splunk.com/app/2665/
This search should have most of the details you want.
| rest /services/saved/searches
You'll have to join it to the _audit index to find out when they were created though