Actually, neither is correct! The US government has stated that the official name of the holiday is Veterans Day, without any apostrophe. The word "Veteran" is used in its plural form, not in any possessive form.
The correct spelling is just as you have used it in your question, Veterans Day. No apostrophe is used because it is the plural form of the word "Veteran" not any possessive form.
According to 5 USC 6103, Holidays (Title 5 United States Code, Part III, Chapter 61, subchapter I) the correct version is "Veterans Day." Veteran's or Veterans' show possession, which is not intended. The intent is to remember veterans on this day, not to show that it is their day.
The VA website just shows it as Veterans Day. There is no apostrophe used. The word "Veteran" is used in its plural form, not in any possessive form.
Veterans Day
what is the importance veterans day
Veterans Day 1955 was a Friday.
Veterans Day 2010 is a Thursday.
Veterans Day 2007 was a Sunday.
Armistice Day .
Armistice Day, Veterans Day, Remembrance Day.
veterans day is November 11th
Veterans.