  We present a new method to estimate time delays from light curves of lensed
quasars. The method is based on chi^2 minimization between the data and a
numerical model light curve. A linear variation can be included in order to
correct for slow long-term microlensing effects in one of the lensed images. An
iterative version of the method can be applied in order to correct for higher
order microlensing effects. The method is tested on simulated light curves.
When higher order microlensing effects are present the time delay is best
constrained with the iterative method. Analysis of a published data set for the
lensed double Q0957+561 yields results in agreement with other published
estimates.
