Synchronization of time is essential for correlation of sensor data. For body area network the sensors are distributed over multiple sensor nodes located on different parts of the body. When collecting sensor data using wireless sensor networks, the delay variation can be up to 1000 milliseconds. Physiological sensors, like ECG, accelerometer and gyroscopes, require a timing accuracy in the millisecond range. This paper describes a generic method to provide synchronized timestamps. The method is tested in a Wireless sensor network using Bluetooth and Bluetooth Smart sensor nodes. Results show that the method is usable for correlating sensor data with 50ms sample rate.