Since February, as i couldn't check further, he had similar ones on those dates:
*02/21-23
*03/09
*09/06-07
You must be right, no meaning behind, but as he kept posting messages about cornwatch, harvest, ... throughout the summer, i had hope his tweets could indicate a signal.
(*Sorry if my grammar is not perfect, i'm french)
>>/6793/
>>/6796/