When looking through the reputation tab of your own profile, there are bars for each day, and you click on that bar to get a list of all the reputation changes to your account on that day.
However, mine seems to be bugged. When I click on a bar, it shows me the reputation changes for the previous day. See the picture (from my profile on the main site, mathematics.SE):
I have clicked on the bar representing yesterday, where I got $10$ reputation. However, the list below the graph shows the reputation changes of the day before, where I got $205$ reputation.
This means that if one day I get no reputation (such as Nov 13 in the picture), then I cannot get the details of the day before (Nov 12). There is no way for me to make that page show me what I did to get reputation on November 12.
Techincal details: I run Win7 professional service pack 1 with Chrome 46 at the moment, but the problem has persisted for some time and is reproducibe in Firefox 42.0 and Internet Explorer 11.0