General population health examination surveys (HESs) provide a reliable source of information to monitor the health of populations. A number of countries across Europe are currently planning their first HES, or the first after a significant gap, and some of these intend offering appointments only during office hours and/or weekdays, raising concerns about representativeness of survey participants. It is important to ascertain whether personal characteristics of participants vary by time of day and day of week of data collection, in order to determine the association between time and day of interview and physical examination on the results of data collected in HES.