This question already has an answer here:
I was trying out some queries in Data Explorer and noticed that, column
CreationDate in table
Votes doesn't contain the full timestamp. Only the date part is present and time part is set to 00:00:00.
Have a look at this query.
It would be nice to have the full timestamp. Possible uses of this are determining how many votes are cast immediately after posting, how many are cast within an hour, and so on.
I read the other post where Greg makes the point that:
up/down voting patterns could strongly correlate with other activity on the site (questions, answers, comments).
But, all these details about posts, comments are available with exact timestamp in User's profile as well as in Data Explorer. The exact voting timestamp can be seen in the Reputation tab. So, if I want to guess who voted me, I can do so by looking at this data. Having exact voting timestamp in Data Explorer won't provide any extra information to aid guessing.