IntroductionMany sources of construction management literature explain howto schedule a construction project with continuous working days.Some of them also provide information on how to apply a singlecalendar to the schedule, emphasizing the importance of acalendar-based schedule. The most common way to apply a singlecalendar is directly translating working days to calendar dates~Battersby 1967; Ahuja and Nandakumar 1985; Clough et al.2000; Knutson 2001!. The time data of each activity from thecontinuous working day ~noncalendar! schedule can be simplyconverted to the correspondent calendar date from the cumulativeworking days counted on the calendar. In this way, every activitycan have early and late times as a calendar date format.In the case of construction projects, it is common to havemultiple calendars according to work properties, weather conditions,resource availabilities, and other reasons ~Lock 2000!. In aproject schedule with multiple calendars, each calendar can containa unique working day pattern per week. For example, a constructionschedule can have three project calendars: one for a 3day work week ~Monday, Tuesday, and Wednesday!, another for a5 day work week ~Monday through Friday!, and the other for a 7day work week ~continuous working days!. Then, any activity of