Patent attributes
Techniques are described relating to analyzing user transactions based on time of day of occurrence, and using time of a day as a factor in determining whether a new transaction should be allowed or disallowed. People may have particular tendencies to engage in transaction at certain times of a day. When a new transaction occurs that does not fit a previous pattern, this can indicate someone else has gained access to the account. Past times of transactions can be transformed to a two-dimensional representation that avoids discontinuity. A smoothed probability distribution can indicate a likelihood of whether a new transaction fits previous patterns. If a new transaction is unlikely due to time of day, the new transaction might be denied/prevented from completing. Denial of the transaction may also be based on additional factors besides the time of day.