OED gives a connection between the German verb zielen and the English preposition till. The semantic connection between German zielen and the verb till (cultivating land) seems a bit far-fetched. I would rather see a connection between German das Land bestellen and English to till the land.
I wonder why this connection is not seen or discussed. And it is for me an example of how easily in etymology one sticks to similar words as zielen even when the semantics is doubtful.