Hi there, I worked on retrieving and distilling this dataset at Sift Science. To address your concerns: Yes, time zones are accounted properly. And yes, the number of data points is significant.

As I've said earlier, you can see in the users count that fraudulent users are indeed the lowest at night (which makes sense, since fraudsters sleep as well). However, we are looking at the "fraud rate" (#fraud / all users in a given hour). I'm not sure what you even mean by "misrepresent" the data. The data speaks for itself.