The American Time Use Survey (ATUS) measures how people spend their time, what they spend their time doing, and with whom they spend it. The ATUS interview consists of several sections including an update of key CPS variables, a 24-hour time diary, and several summary questions that clarify and/or augment diary reports. The primary objective of this study was to evaluate respondent accuracy in recalling the occurrence and the duration of the trips away from home. The question was designed to help measure systematic bias that might occur in ATUS because the survey only includes "yesterday" interviews, thus missing activities done on trips away from home lasting more than 2 days. Researchers examined the effect of the recall period on reporting accuracy and identified meaningful trip purpose categories. Based on the testing, several recommendations were made including lead-ins to these "missed day" summary questions and the use of a backwards-recall strategy to collect information about multi-trip months. A recommendation was also made that the ATUS restrict the recall period to two months or less to facilitate accurate recall.