The problem is at the end of a two line display. Pic above. I guess the " " just pushes the junk over the edge, possibly to return on January 1st.
Not exactly. Yours is not a viable solution if you ever intend to use a different message format or a display with different geometry. The junk did not get pushed over the edge, it just got put in the closet. It is still in the controller memory but it is in a memory location that does not correspond to a visible character on your display. Follow the LCD Addressing link at http://web.alfredstate.edu/weimandn to see all the gory details.
Don