The "yelda" experienced by Amir also represents the first time in his life that he feels an intense attachment to another person.
Even though Amir spent enjoyable past yeldas with Hassan, they did not resonate in the same way as the yeldas of his courtship years.
The text tells us that Amir endured an ambivalent, conflict-ridden relationship with Baba during his childhood. While Hassan's friendship proved a great comfort during these turbulent years, Amir never formed a deep attachment to his most loyal friend.
In contrast, during his courtship years with Soraya, Amir felt as if the nights seemed to endure forever. He could not wait for morning, when Soraya's presence could once again grace his existence. The text tells us that every night of the week became a yelda to Amir after he met Soraya. He was so infatuated with her that he invented many excuses to stop by the Taheri family's stand at the flea market.
Often, Amir spent many sleepless nights in bed until the day of the flea market, when he could see Soraya again. So, in Amir's courtship years, the yeldas symbolized agonizing periods of waiting and longing.