# Shorter time steps than one hour

For a WaSiM application, the time step duration must be defined per sub model - it is not recommended to set different values for different sub models, so the usage of a common variable (usually $time) is strongly recommended). The minimum time step is 1 minute. Meteorologic input data must be provided in the temporal resolution, the model should run in. If the model time step is shorter than one hour, the date entries have to be repeated as often is required to fill up one hour with the smaller time steps (note that the time step must be an integer divisor of 60 minutes, e.g. 15 or 10 minutes or 5, but not 13 minutes or 18 or 25 or so). See also the figure below: The time step is 10 minutes here, so the date entries are repeated 6 times for each hour.