There are 10 federal holidays in America, but universally they only observe New Year's Day, Independence Day, Labor Day, Thanksgiving and Christmas Day. Some states observe a few more holidays and not include a few from the list below. Some states celebrate them, but on different dates.

Date/Day

Holiday

1st January

New Year's Day

January (Third Monday)

Martin Luther King's Birthday

February (Third Monday)

President's Day

May (Last Monday)

Memorial Day

4th July

Independence Day

September (First Monday)

Labor Day

October (Second Monday)

Columbus Day

11th November

Veteran's Day

November (Fourth Thursday)

Thanksgiving Day

25th December

Christmas Day


For holiday list for US consulates in India visit:

http://mumbai.usconsulate.gov/holidays.html

Before going to the consulate, make sure that it is not any of these days. Secondly, if you are planning to travel on any of the holiday's, then it is always advisable to get the booking one month in advance, as it will be overbooked on holidays. Specially in December i.e. at the time of new year and christmas, it is very difficult to get the confirmed booking at the last minute.