How should one deal with null values in time stamp data types? I have a data set where certain features are time stamps for certain important events like time stamp of when a user logged in etc. How should I deal with null values in such cases. Should one just replace null values with current or most recent time stamp. Are there any standard techniques followed ?
Leave those time stamps null in order to indicate that you do not possess the time of those events. Everything else depends on the logic of your application.