'djdj', you certainly have your right to disagree with my advice. But, I can certainly see why, as you claim, you have to deal with landlords all the time. With the attitude that you have, you must have to move all the time, and have probably been sued a lot.
Oh, and you need to go back and read the citation that you offered (§ 8-208.2). You have done what a lot of 'quasi-experts' do. That is to find a few words in a statute or code that LOOK like they apply, and throwing it out as the answer. If you will really read the FULL statute, you will see that it only applies for rental property (usually commercial leases) where a violation of "real property subject to the provisions of Title 6, Subtitle 8 of the Environment Article...". There have been NO claims that this rental issue has to do with Environmental issues!!
Further, you claim that "Holidays" are not counted in calculated days of late rent. That is simply not true, UNLESS STATED AS SUCH IN THE LEASE. The reality is that it is up to the tenant to take the holiday into account and make the payment early enough to be received within the grace period. You need to learn something about contracts (that is what a lease is), simply, both parties can ONLY do what is specifically granted in the contract and in compliance will the local laws. There are NO 'extra' allowances, real or imagined. If you have 'pulled the wool' of extraneous 'conditions', it was only with the grace (or ignorance) of the other party.
Oh, and 'djdj' and I agree on one more item... I would also refuse entry to the landlord for the sole purpose of 'showing to prospective tenants'. Unless your lease provides for this access, it is not allowed. The lease is a two-edged sword. It gives the landlord certain rights AND it gives you rights. One of your RIGHTS is the right to security and privacy. The landlord will very probably violate your rights if he/she exercises unconditional access in violation of the lease provisions. If he/she does this, you probably have the right to file criminal trespass charges (and possibly burglary) on him/her. The problem that the tenant will have is proving that the landlord entered for purposes not allowed in the lease. Can you set up a video camera with 6 hour record for while you are at work?? Can you have a friend 'house-sit' while you are out?? Can you have a neighbor watch the premises??
'Livin in MD', we are in agreement on one thing though... it seems very unusual for a landlord to be trying to evict you for the reasons stated... two late payments with penalties paid. And there is probably a good chance that this landlord will not be granted a Writ of Detainer. However, we must believe that there is more to this than stated.
My suggestion is...
Send the landlord a letter (Certified RRR) detailing that you are in full compliance with the terms of your lease and that you intend to continue in compliance. Detail the circumstances of the two late payments, and that you have paid the fees and penalties as required by the lease (this 'amends' any claim of breach). State that the lease provides you certain legal rights of privacy and security, and that you expect the landlord to comply with them. Add that any violation of your rights by the landlord, or his/her agents, will be prosecuted (as you already know he/she would against you).
I would DOCUMENT each and every thing that they landlord does or doesn't do per the lease. You may very well need this if (when?) this matter goes to court, it sounds like that might be where you are heading.
One final item... with the turmoil that you already have experienced with this landlord, you might want to offer to negotiate an early termination of your lease, providing that the landlord compensate for your moving expenses, etc. Otherwise, this landlord will be on you for every transgression. (Personally, I would strongly suggest this.)