Actually, I would argue this is non-trivial. True, the start times of the individual jobs called by Build Flow DSL are recorded elsewhere, but an awful lot can happen either side of the DSL, for example a source checkout, or a bunch of post-build activities.

Not having any timestamps in the console output of this kind of job is a major annoyance. Please can you raise the priority?

Richard: changed priority to 'Major'

Being groovy can always add your own, though would be nice if the option was supported

println "job scheduled at" + new Date()
build("job")
println "job completed at" + new Date()

It seems that the timestamp is fully compatible with the Build Flow plugin, but it cannot be enabled through the UI due to Build Flow job types not having a "Build Environment" section.

As a quick PoC, I tried added the timestamper wrapper config to the job's config.xml directly. After doing this the subsequent builds displayed timestamps as if it had been enabled normally. The downside is that as soon as the project's configuration is changed through the UI, the manual addition is removed

Not only is the Build Flow plugin deprecated, but distribution of it has been suspended due to unresolved security vulnerabilities. Therefore, I am closing this bug as "Won't Fix."