I've just hit 'build' on a host I originally built a few days ago. On the host page and dashboard the 'build duration' displays '3 days'.

Following these debugging steps here. https://community.theforeman.org/t/what-is-build-duration-and-how-is-it-determined/11051/5?u=afisher

irb(main):002:0> host.initiated_at
=> Mon, 25 Feb 2019 11:18:08 UTC +00:00
irb(main):003:0> host.installed_at
=> Fri, 22 Feb 2019 17:13:38 UTC +00:00

Looks like `initiated_at` was reset, but even though `installed_at` is an earlier date, the difference is still calculated and '3 days' displayed.