Presented in “Living Together: Planets, Host Stars and Binaries” workshop, September, 8 – 12, 2014, Litomysl, Czech Republic

We develop a python-based GUI code, Xtrema, that can be used for calculating the times of minimum for eclipsing binary systems as well as the maxima of pulsating stars. Xtrema performs minimum/maximum time determination from multi-cycle light curves (i.e., 1000) such as from Kepler/CoRoT data, using different methods, and also provides error estimates. Despite the coarse sampling rate of the long cadence Kepler data, Xtrema can be used to determine reliable times of minimum/maximum by combining successive minimum/maximum profiles as defined by the user.