It does not matter how "close" you are to your coworkers or how much time it takes to replace you. As mentioned above, depending on where you live, 2 weeks is the standard maximum in the United States. Whether you give them 2 months (which is ridiculuous) or two weeks, you will leave on the same good note. This is what we all want out of our jobs, a good note and to not burn any bridges. My husband and I both work at the same employer and yes, are two weeks notice will be given at the same time. The company is my husband's long turn career and he will transfer wherever we go, and depending on funding, I will most likely do the same.