How to parse ISO 8601 durations?

findus_l 

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 
Usage
| 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