How to parse ISO 8601 durations?

New Contributor

In Azure Log Analytics Queries, is there a way to parse ISO 8601 durations to use in comparisons? The format looks like this: PT1H29M58.163977013S

More information on the format can be found here: ISO 8601 - Wikipedia
2 Replies



I did start to write a function for this, but never went back to it, here is where I got to (limited testing but maybe it will give you or others an idea).  It only deals with D,T,H and in a basic way.

let a = "PD1T1H29M58.163977013S";
// use Usage as it always exists 
| extend d = extract("D([0-9]+)",1,a, typeof(real)) * 1440  //convert mins 
| extend h = extract("T([0-9]+)",1,a, typeof(real)) * 60    //convert hours to mins
| extend m = extract("H([0-9]+)",1,a, typeof(real)) 
| extend newDay_ = strcat(d + h + m,"m")
| where TimeGenerated > ago(totimespan(newDay_))
| project-away d,h,m


Thanks. Having this extra makes a query harder to read and harder to maintain. How is there no existing function for this.