In clinical trial data, we often encounter partial dates (one or more components of a date (year, month, day) are not known). For analysis purposes like calculating approximate durations, we fill the missing components with prespecfied values. This process is called date imputations. In ADaM, if an imputed date value is stored in any analysis date variable (ADT, ASTDT, AENDT etc) we use date imputation flag variable -DTF to indicate the level of imputation performed. -DTF will have a value of Y when Year is imputed, M when month is imputed, D when day is imputed. Similarly, for time imputations, we use -TMF variable to indicate the level of imputation. -TMF will have a value of 'H' if hour is imputed, 'M' when minutes are imputed, 'S' when seconds are imputed.