Timestamp of jobs completed vs started.

I am trying to piece together as to why some jobs are not available for restore etc. I have looked the timestamp of when jobs start and when they finish.

I try and aggregate the data with when .FH files are created and try and match up times. But the time that jobs start and finish do not match up with when ctalog files are created.

My Question is:

If a job starts on the 1st of the month at 10pm and the job finishes on the 2nd of the month at 6am, when will the .FH file be created?