I keep looking this up so thought I would clearly document it for myself and the rest of the interweb.
When troubleshooting Configuration Manager Maintenance Windows the runtime number in the ServiceWindowManager.log is in seconds
OnIsServiceWindowAvailable called with: Runtime:6600, Type:2
6600/60 = 110 minutes
(6600/60)/60 = 1.83 hours, Or 1 hour and 50 minutes