convert run_duration (DD: HH: MM: SS) column to Seconds.

Hello,

I am trying to convert run_duration (DD: HH: MM: SS)  column to Seconds. 

For example, if Run duration is 1 Day: 1 hour: 1 minute: 1 second I need to convert it to 90061 seconds

86400 + 3600 + 60 + 1 = 90061.

Thanks