For the file/stream lines: The need for the interval time is straightforward to understand, I imagine, and so is the needs for the actual histogram. The max value is there for human readability and ease of very-simple-parsing for timeline plots. I.e. if you want to just plot a max-value-per-interval chart (which is very useful next to a percentile distribution chart. E.g. in jHiccup-style plots), you only need the max value, and that can be scraped out of this log format with awk, without needing to decode histograms.