Unfortunately, the ACGME has not come down hard on this type of behavior and essentially says, "its up to the program as to how they define it." From the ACGME FAQ:
Residents must be provided with 1 day in 7 free from all educational and clinical responsibilities.
Question: The common duty hour standards state that residents must be provided with 1 day in 7 free from all responsibilities, with one day defined as one continuous 24-hour period. How should programs interpret this standard if the day off occurs after the residents on-call day?
Answer: The common duty hour standards call for a 24-hour day off. Many RCs have recommended that this day off should ideally be a calendar day, e.g., the resident wakes up in his or her home and has a whole day available. Others have noted that it is not permissible to have the day off routinely scheduled on a residents post-call day.
Having the day off always occur on a non-post-call day may be difficult to implement in some small programs, but the requirement for a rest period after in-house call would take part of a postcall day, making it less than a full 24 hours free of program duties. Because call from home does not require a rest period, the day after a pager call may be considered 24 hours off. Other RCs have not been as explicit, but would likely not consider it appropriate to have the residents day off regularly scheduled on their post-call day.
It's actually worse. 1 in 7 days is what the AVERAGE schedule has to show. In other words, my friend has worked 26 days in a row but got the first two and last two days of the month off. This poor bastard has to go in at 5:30am Friday, get's off Sat. morn. around 9am...then GOES BACK IN SAT. NIGHT AT 8pm. Absolutely ridiculous.