You need a space before the #.

Problematic code:

while sleep 1
do# show time
  date
done

Correct code:

while sleep 1
do # show time
  date
done

Rationale:

ShellCheck has noticed that you have a keyword immediately followed by a #. In order for the # to start a comment, it needs to come after a word boundary such as a space.

Exceptions:

None.