This paper presents a new empirical approach to address the problem of trading time differences between markets in studies of financial contagion. In contrast to end-of-business-day data common to most contagion studies, we employ price observations, which are exactly aligned in time to correct for time-zone and end-of-business-day differences between markets. Additionally, we allow for time lags between price observations in order to test the assumption that the shock is not immediately transmitted from one market to the other. Our analysis of the financial turmoil surrounding the asian crisis reveals that such corrections have an important bearing on the evidence for contagion, independent of the methodology employed. Using a correlation-based test, we find more contagion the faster we assume the shock to be transmitted.