Hi, vxmehra98,
Yes, they were open on 20th, which is the third Friday of month and on which the office is normally closed. And I had a vague memory that they trade 20th to some other day during holiday.
My assumption is either 24th (Christmas eve), 26th (day after Christmas), or 31th (New year's eve). If you get more info on this matter, please let me know. I plan to go there sometime before the end of this year. Also, if you are applying for AP, EAD, I am wondering if you can let me know whether you get it in one day or not.
Thanks,
Accord