Each rent period entered must be a full period. However, you can select varying payment lengths, including Daily or One-Time. If you have an irregular payment period, you can enter it as a One-Time period with the full rent amount entered, with the step ending the day before the next rent period starts.
For instance, if your lease starts on March 10 with a payment of $2000, then on April 1 starts regular monthly payments of $3000, you can enter two rent steps. The first step is One-Time, starting March 10, ending March 31, with a gross rent of $2000. The third step has rent of $3000, and continues until the lease ends (or the rent changes).
If such a lease is operating and doesn't have any other rent changes, you may want to turn off rent leveling, as the rent really is not changing and the effect of leveling would be marginal, but might result in a few pennies of activity due to rounding issues which would then have to be tracked. If the partial month is an exact prorate of the regular monthly rent, EZLease will recognize that and not initiate rent leveling.