NYS IT-203-A: do I need to complete days allocation and then 203-a to allocate business? I assume that the number of days in NY determine the allocation of corp income?

Its seem that IT-203-A is duplicate.  during the question process in TT, I determine my NYS business income by number of days in NYS versus outside of NY.  I work for corporation and don't earn income by the state I work in.  So number of days is best course to assess allocation percentage.  But a few questions later, I'm asked if I need to complete 203-A to allocate, can the answer be NO and delete the form?