1. A drug delivery system adapted to estimate time parameters for a medical regimen comprising one or more administering events at a given time within a given period, comprising: a controller, a drug reservoir or structure for receiving a drug reservoir, drug expelling structure for expelling an amount of drug from the reservoir, wherein the expelling of an amount of drug requires at least one user-actuated operation to be performed, and wherein the expelling of an amount of drug represents an administering event, the controller being adapted to: detect when a given user-actuated operation being part of the expelling of an amount of drug is performed, record detected operations as a function of time, and estimate, based on recorded operations, regimen time parameters for the detected operations, including: the periodicity, and a time or time window for each operation in the estimated period, thereby providing estimated time parameters for a medical regimen on which the detected operations are assumed to be based upon.