latch

	  if slow_clock = '1' and slow_clock'event then
		if pm = '0' then 
		     if latched then
			case month is
				when Jan =>
					latched <=false;
					"executions here"
					
				when Feb =>
					latched <=false;
					"executions here"
				and so on
			end case;
		    end if;  -- { if latched }
		else
		    latched <= true;
		end if;		-- if pm = '0'
	end if;		-- if clock
	
this effectively execute the statements in the states only once.