Nessus data charting- How to make a trend chart of specific data set?

[jenkinsta]

I am making a trend chart of specific data set. What I am looking for is (generic example)

index=nessus | eval Month=strftime(firstSeen,"%b") | chart count by severity Month

So the end result would be Months on the X axis and the count of severity (critica,high,medium) for each month. Each month would have a count of each severity.  But using the firstseeen date from the date event. 

[yeahnah · Accepted solution]

Hi @jenkinsta 

I think timechart would be better suited for this.  Something like

index=nessus
| timechart span=1month count BY severity 

 The counts are group by month then

Hope that helps

[jenkinsta]

Thanks, I can do it by the time of the event but what I am looking for is by the firstSeen value from the event itself. 

eval FirstSeenMonth=strftime(firstSeen,"%b")

How can I group by FirstSeenMonth or is there something else I need to do before I do any charting?