This looks like a variantion of a pigpen cypher. The first row transposed on a clock reads as follows:

1,_,6,8,11

1,4,_,8,11

1,4,6,_11

1,_,6,8,11

1,4,_,8,11

1,4,6,_,11

1,4,6,,

,,6,8,11

1,4,_,8,11

1,4,6,,

,,6,8,11

Seems really sequential to be accidental.

Does this mean anything to anyone?