Abstract: The present disclosure provides techniques for sensor event based activity hour modelling. A processing device obtains, via a sensor application installed on a user device, a plurality of events occurring on the user device, where each event in the plurality of events includes a respective day and a respective time. The processing device aggregates, based on the respective day and the respective time, the plurality of events to generate time series data. The processing device performs a smoothing operation on the time series data to generate a curve. The processing device classifies an event on the user device as usual or unusual based on a baseline level of activity on the user device and the curve.