Sometimes 2 or more models have to be merged. Sometimes these models have been made with both a level with each a different timestep. When these models have to be merged, we have to interpolate one of the levels before merging the levels together. It would be easy that ICM interpolates the level. Also this is needed when an additional outfall has been created for which the (by a watercourse manager) delivered water levels (that are going to be used as a level). Since the levels are made by 1) copying the original level, 2) changing the timestep and interpolate again the values so the original water levels are again at the correct timestep and 3) add the new profile. So the idea was to, when changing the timestep, ICM will ask what to do: a) fit the existing value in the new timesteps and interpolate the timesteps in between, b) leave the timesteps in between on 0 or c) make a constant for the timesteps in between. For example: let's say the level on timestep 5min is 10 mAD and at 10min it is 3 mAD. When we then change (for whatever reason) the timestep to 1 min, it would be useful that for each timestep in between (6, 7, 8 and 9 mins) the level would be determined by ICM. In our idea for a) 9 mAD, 8 mAD, 7 mAD, 6 mAD for b) all 0 or c) all 10 mAD.