On the main screen, the data is shown for the last 12 hours. This means that a range is shown as "28 Feb 2016, 22:35 - 10:35", for instance. If the second date is "today", this information is ignored. So, the above example should instead read "28 Feb 2016, 22:35 - today 10:35" or, in the worst case, "28 Feb 2016, 22:35 - 29 Feb 2016, 10:35". Ideally, though, it would read "yesterday 22:35 - today 10:35".