Related על ראש השנה 24:13

How [one should understand]: "for the vows"? [Answer:] If one has been forbidden by a vow to use another for a year, he counts twelve months from this specific day and onward. But if he says: For this year, even if he has denied himself the benefit of it by the vow only on the first in Elul, [the obligation] is only up to the first of Tishrei.