ZIP code 01366 is officially located in the state of Massachusetts, primarily serving the city of Petersham. It falls under the administrative jurisdiction of Worcester County. When planning mail delivery, logistics routing, or demographic research, 01366 operates within the Eastern Time (ET) timezone and supports the 563 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 01366 ZIP Code Tabulation Area is approximately 36,963. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $62,366.