A computer-implemented method is presented for synchronizing time between two handheld medical devices that interoperate with each other. The method includes: determining a first time as measured by a first clock residing in the first medical device; determining a second time as measured by a second clock residing in a second medical device; evaluating whether the first clock is synchronized with the second clock; determining whether at least one of the first clock and the second clock was set manually by a user; and setting time of the first clock in accordance with the second time when the second clock was set manually by the user.