I'm renting a furnished rental in Washington state, month-to-month. Before signing the leese, the landlord was verbally informed I could not give extended termination notice due to the nature of my job; I assume that's why he crossed out the paragraph on "Lesee's Hold Over" which states:
"If leesee remains after natural expiration of agreement, a new tenancy from month-to-month shall be created which shall be subject to all terms and conditions hereof except that rent shall then be due and owing at ___DOLLARS___ per month and except that such tenancy shall be terminable upon 30 days written notice served by either party."

Other than that crossed-out paragraph, nothing in the leese requires giving notice to vacate. I've since informed the landlord I'm moving out in 12 days. His first response was to complain he didn't get 30 days notice! He later researched WA state law and discovered he can only demand 20 days. Now he wants to charge me another month for not giving 20 days notice - even though he crossed out the only thing remotely related to that in the leese. Am I liable for an extra month because this unscrupulous landlord didn't stipulate his notice requirement in his leese?

On a related topic, what constitutes one rental month in Washington state? Is it 30 days, or, for example, Feb 5 to March 5? Also, when does a "term" begin if not specifically noted in a leese (mine simply says "month-to-month"?). Is it the day one moves in or the day the leese is signed?

Thanks in advance for your help,
Oliver