When exactly did Ya'akov ask Lavan to be given Rachel?
(29,21) “And Ya’akov said to Lavan: Give me my wife, for my days are completed, that I may come to her.”
Rashi explains that the phrase “my days are completed” refers to the “few days” that his Ya’akov’s mother had said he should dwell with Lavan (Bereishis 27:44). But the Ramban asks why Rashi does not explain that the posuk means that the seven years of work which he had contracted to do in order to marry Rochel were completed, since this is the more obvious explanation!
But it seems to me that we can explain Rashi very well according to the gemora in Kesuvos 57a, which teaches that from the time that the husband indicates that he wishes to complete the marriage with his wife, she is given a period of twelve months in order to complete her preparations for the marriage. And this law is learned from that which the household of Lavan stated when Eliezer wished to immediately take Rivkah back to Yitzchok - “let the maiden stay with us some days or ten” (Bereishis 24:55), and the gemora proves that the phrase “some days” means twelve months. From this we see that the household of Besuel and Lavan observed this rule of giving a virgin twelve months from when the husband claims her.
According to this we must ask that if Ya’akov was already eighty-four years old and thus in a hurry to fulfil his mitzvah of having children, how was it that he was not careful to claim Rochel twelve months before the completion of his work contract, since Lavan might insist that he wait another twelve months! We cannot answer that maybe he did indeed come twelve months before the end of his contract, because then he should not have said “my days are completed” but rather "my days will be completed".
However, we could resolve this problem by saying that Rochel was already an adult at that time (i.e more than twelve and a half years old). We can bring a proof for this from Yitzchok’s telling Ya’akov to go to Padan Aram to take a wife from the daughters of Lavan, which implies that she had already been born when he said this, and we know that Ya’akov spent fourteen years in the Beis Medrash of Shem and Ever before arriving in Haran. And since she was already an adult she would only have been given thirty days to complete her preparations, not twelve months. But even if we say this we still have the question why he did not come thirty days before finishing his contract, since his words seem to indicate that he had already completed his contract, as we explained above.
This is why Rashi explains that “my days are completed” must refer to the days that his mother had fixed for him, and if so we can explain that he did indeed come thirty days before his contract was completed. Because the few days, that is, the seven years that his mother had told him that he needed to stay with Lavan started from when he arrived in Haran, but he did not start his contract of seven years work for Lavan until a month after his arrival.
Thus, when the seven years that his mother had fixed for him were completed he still had a further thirty days of work to complete, and so by coming to Lavan at that time to ask to marry Rochel, the thirty days that she was then given to prepare herself finished at exactly the same time as his contract finished. And thus the explanation of Rashi is precise and correct.