A compare tries its matches arms from top to bottom and runs the first one that fits. If a later arm matches a value an earlier arm already handles, the later arm can never run – and Turf treats that as a mistake rather than letting dead code sit quietly, because it nearly always means one of the two arms was meant to match something else.
compare day { matches 1: ... done matches 2: ... done matches 1: ... done // 1 is already handled above}Either change the repeated value to the one you meant, delete the extra arm, or – if both arms should do the same thing – stack them so they share one body:
compare day { matches 1: matches 7: ... done // 1 or 7 matches 2: ... done}(A different situation: an arm that can never run because an earlier catch-all arm matches everything – matches _: – is only a warning, E094.)
Run turf --explain E133 in a terminal to read this again.