A diabetes therapy device is disclosed herein, which includes a profile memory storing a parameter profile and a dedicated reference time mark. The parameter profile defines at least one parameter that is associated with insulin administration as a function of time for a generally circadian chronobiological cycle. The reference time mark indicates the beginning of the circadian chronobiological cycle and initializes a running time. Insulin amounts to be administered are determined as a function of the running time in accordance with a current matching of the parameter profile. A modified matching based on the reference time mark and an upcoming trigger time is computed and is time-shifted from the current matching, wherein the modified matching is applied by making the modified matching the current matching, such that future insulin amounts to be administered are determined in accordance with the modified matching.