cafepress has an opening in our technical support area, details attached.
current configuration is 4 12-hour day shifts (8a ET - 8p ET) one week, 3 12-hour shifts the next. precise days under review, but could include one or both weekend days. once the cycle is established, it doesn't change. the days are contiguous in a given week. an *example* is "monday, tuesday, wednesday, and every other sunday".
email me directly if you're interested or have questions.
thanks.