My response:
The following are CALIFORNIA CODES from our CIVIL CODE, written here only as an example of how California deals with contractual situations of the type you describe. I cannot imagine that Florida does not have something similar in it's laws.
7. Holidays within the meaning of this code are every Sunday and
such other days as are specified or provided for as holidays in the
Government Code of the State of California.
7.1. Optional bank holidays within the meaning of Section 9 are:
(a) Any closing of a bank because of an extraordinary situation,
as that term is defined in the Bank Extraordinary Situation Closing
Act (Chapter 20 (commencing with Section 3600) of Division 1 of the Financial Code).
(b) Every Saturday.
(c) Every Sunday.
(d) January 1st.
(e) The third Monday in January, known as "Dr. Martin Luther King, Jr. Day."
(f) February 12, known as "Lincoln Day."
(g) The third Monday in February.
(h) The last Monday in May.
(i) July 4th.
(j) The first Monday in September.
(k) September 9th, known as "Admission Day."
(l) The second Monday in October, known as "Columbus Day."
(m) November 11th, known as "Veteran's Day."
December 25th.
(o) Good Friday from 12 noon until closing.
(p) The Thursday in November appointed as "Thanksgiving Day."
(q) Any Monday following any Sunday on which January 1st, February 12th, July 4th, September 9th, November 11th, or December 25th falls.
(r) Any Friday preceding any Saturday on which July 4th, September 9th, or December 25th falls.
10. The time in which any act provided by law is to be done is
computed by excluding the first day and including the last, unless
the last day is a holiday, and then it is also excluded.
11. Whenever any act of a secular nature, other than a work of necessity or mercy, is appointed by law or contract to be performed upon a particular day, which day falls upon a holiday, it may be performed upon the next business day, with the same effect as if it had been performed upon the day appointed.
IAAL