I started this school year as a sub, after 2 weeks I started my student teaching, then applied for and received my credential. I have since gotten a teaching job in another district but am still on the sub list in the district I started the year in. The district I am working for has a day off next week and I would like to sub that day in my original district. I told a teacher friend of mine my intentions and he warned me that it might be illegal and be considered "double dipping". Never heard this term (sans Seinfeld).