Memorial Day is an American holiday, observed on the last Monday of May, honoring the men and women who died while serving in the U.S. military.
You Cannot carry in a National Cemetery
VA regulations 38 CFR 1.218 prohibit the carrying of firearms (either openly or concealed), explosives or other dangerous or deadly weapons while on VA property, except for official purposes, such as military funeral honors. Possession of firearms on any property under the charge and control of VA is prohibited. Offenders may be subject to a fine, removal from the premises, or arrest.
This includes parking lots adjacent to or part of the facility if the Federal Agency/Entity owns or has control of the parking lot and it is posted “No Firearms”. The lot has to be posted under federal law if they do not wish to have firearms present.