We derived minima times from the transit light curves of Kepler-412, Kepler-422, Kepler-427 and Kepler-435 observed by Kepler space telescope, using Kwee and van Woerden method and Gauss function fitting. All data were collected from NASA Exoplanet Archive in PDCSAP format with the wget command directly from operating system console. Minima times were determined with two different methods; the first one is AVE soft-ware which uses Kwee and van Woerden method and second, Gauss function is written in R statistical program-ming platform. We examined the Observed minus Calculated (O-C) diagram of each system separately, modelled them with linear and quadratic functions. We obtained that linear models give best fits for the O-C diagrams. Parameter uncertainties were estimated by using the Maximum Likelihood method. We calculated dominant fre-quencies without any statistical significance on Lomb-Scargle periodograms limited by Nyquist frequency window, as implied by the false alarm probability, FAP of each object. We extracted the noise and considered them as a scale of the measurement uncertainties. We presented updated light elements of systems and concluded that linear models of O-C diagrams are the best fits to the data.