There are three questions, really - but the first is the most important.
1. Can you get the reporter to record the duration since the last batch in seconds (or ms) in the same row as the current batch?
2. Can you get the reporter to record the timestamp in the report rows as ms since epoch (preferrably alongside the regular date in a different column, but by itself it'd probably be ok)
3. Is there any way to hook into the reporter output to customize how it records the actual data?
The jmx reporter records the batch number and the date of the batch run, but I don't see an easy way to get it to record the current date as a MS timestamp.
I've thought about creating a simple custom MBean that existed to do nothing but expose the current time in ms since epoch as an attribute that I could then have the reporter use and include a column both for the absolute date and for the relative date. Having certain metrics reported in terms of # of events / second would make it easier to analyze certain data (for instance, instead of showing the total ReadTimeMillis if it would show ReadTimeMillis / Reads / # ms * 60 to get the average time for a read, that would be a lot more useful for comparing intervals)
The intervals are never run on exactly the same schedule because the timer starts after the last report runs and the duration of running all the reports is not uniform.
(It'd also be very nice if the outputting of the reports were configurable and there was a way to plug into the reporting engine to hook in a different output method - e.g. to a database or to send the data over UDP to a graphite server or something)