My agent chose an 18 day closing period. Is this normal?

[Moises Guerra Garcia]

The offer was accepted late Monday evening (October 3rd, 2022). The closing date chosen is October 21st. My agent chose this date. There are 18 days between these 2 dates. 

Since this is my first time purchasing a home, I didn't put too much thought into it. Today I decided to consider other lenders to see if I get a better rate. The Bank of America mortgage banker, who I spoke with on the phone and who was working on giving me a loan offer, was baffled by the 18-day period. The banker mentioned this period is usually 30 days. During this call, I learned a bit about the steps that take place during these 30 days (closing period). One step I recall right now is the lender appraisal. The banker recommended that I talk to my agent to get that change, otherwise, I could lose the escrow and option fee money on the closing date since the bank will not have enough time to get everything done by this date. 

Is there any reason perhaps that my lender chose this date as the closing date? What is the reason behind such a short closing period?