It is established that the day Sydney walked in the CIA building and met Vaughn ( in "Truth Be Told") was October 1st.

Vaughn: (to Sydney) This watch belonged to my father. It's broken now, but it used to keep perfect time. And when he gave it to me, he said, "You could set your heart by this watch." It stopped October 1st -- the day we met.

Marshall: (to Sark) Hi. Welcome. Don't kill me.

Sydney: (to Sark) I'm here to remind you what I hope is obvious but I don't wanna overestimate your intelligence. If you burn me, I burn you.

Kendall: Do you know where the nukes are?
Irina: Yes, I do.
Kendall: Where?
Irina: I've spent the last thirty-six nights lying
on a steel mattress.
Kendall: And what the hell is that supposed to mean?
Irina: It means I would appreciate a pillow and blanket.

Irina: (to Sydney) You're so willing to take risks for your country. Why aren't you willing to do the same for your own happiness?

Irina: Your last name's Akhtar, but your accent has a trace of Hindi.
Saeed: My mother is from Jammu.
Irina: Your parents were brave to marry, knowing the prejudice they'd face.

Hindi is a language spoken in most states in northern and central India and 'Akhtar' is a Pakistani name. Irina's remark about prejudice between India and Pakistan relates to the Partition of India in 1947 when the colony of British India was divided into two independent nations - India and Pakistan. This Partition was a extreamly controversial and the cause of great tension between the nations.