In the episode Evolution of the Daleks the sole remaining Dalek, Dalek Caan initiates an emergency temporal shift to escape.
The last time we witnessed a Dalek use this method of escape was in the episode Doomsday, which introduced the Cult of Skaro and which saw Dalek Sec and the other Cult member Daleks shift from roughly contemporary London to Thirties New York. This is a short journey, both spatially and temporally, presumably because of the vast amount of energy such a process uses. Is it possible that Dalek Sec used his superior power to use his Shift Filed to take the other three cult members to the thirties, thus weakening himself to such an extent that his judgment became skewed and he began the ill received human-Dalek hybrid project.
Dalek Caan has the ability to time-shift but as a comparatively low caste, and therefore low spec. Dalek he can only shift a few years and a few thousand miles on the surface of the planet. This leads to the idea that the one place on Earth in the first half of the 20th century most suited to the Dalek philosophy is Germany under Hitlesr and National Socialism and leads me to a chilling vision in black and red with chromium and steel accessories… the Nazi Dalek