Top: light curves for DES J0408−5354  obtained in the R_c filter with the MPIA 2.2 m telescope and the WFI instrument. The points obtained with the 1.2 m Euler telescope are also shown with larger and thicker symbols. To guide the eye, the structure constraining the most the AB time delay is indicated between black solid lines. Bottom left: spline-fitting of the intrinsic quasar variations (with an initial knot step of η = 15 days) and time delay determination when neglecting extrinsic variation due to microlensing. The time delay values do not depend much on the choice of this η parameter, which is only an initial value optimized during the fit. Bottom right: same as bottom left but now including extrinsic variations (colour curves). For more clarity the lower S/N Euler data are only shown in the top panel. Our light curves are available at the CDS and on cosmograil.org.