as well as Start Time and End Time; show a column displaying how long ago - relative to the system time - the build took place

Developers are based all over the world - often in different timezones to the ones that are running CI builds. So knowing a built took place at 8:12 is not that relevant unless the end user knows the local time of the machine and (ii) is good at doing mental timezone-changing. What is more helpful is the build took place 5 hours ago.

So either allow a timezone to be specified per user so all times can be auto-converted - or just show how long ago a build took place.

Maybe it'd be neater to have these columns

Start Time (on machine) : Duration (how long the build actually took) : When (how long ago it took place from now)