The authors examine variation in employed fathers' time with children ages 0 to 14 years, using time use surveys from the United States (2003), Germany (2001), Norway (2000), and the United Kingdom (2000). They examine levels of father involvement and mechanisms associated involvement on both weekdays (N = 4,192) and weekends (N = 3,024). They find some evidence of "new fathers" on weekends in all countries. Fathers spend more time on interactive care and more time alone with children on weekends than on weekdays. Only Norwegian fathers, however, increase both their participation in and time spent on physical care. American and British fathers' time with children, however, is more responsive to partners' employment. (Contains 6 tables and 5 notes.)