Hi Anamaria,
Thanks for these interesting paragraphs.
I guess your criteria was that these were holidays celebrated by more than one nation.
For single nations. There are other holidays in July,
Canada Day July 1: 
Canada Day
Background
On
June 20, 1868, a proclamation signed by the Governor General, Lord
Monck, called upon all Her Majesty's loving subjects throughout Canada
to join in the celebration of the anniversary of the formation of the
union of the British North America provinces in a federation under the
name of Canada on July 1st.
US Independence Day July 4:
On July 4, 1776, we claimed our
independence from Britain and Democracy was born. Every day thousands
leave their homeland to come to the "land of the free and the home of
the brave" so they can begin their American Dream.
The United States is truly a
diverse nation made up of dynamic people. Each year on July 4,
Americans celebrate that freedom and independence with barbecues,
picnics, and family gatherings. Through the Internet we are learning
about and communicating with people of different nations, with
different languages and different races throughout the world. Bringing
the world closer with understanding and knowledge can only benefit all
nations.
We invite all nations to celebrate with Americans online this Fourth of July.
Happy Birthday, America!
Utah Pioneer Day July 24
Utah's State Holiday
July 24, Pioneer Day is a Utah state holiday. On this day we celebrate the pioneers' settling in Salt Lake.
The 24th is a huge holiday for Utahns, even bigger than July
4th. There are more parades and fireworks displays during the Days of
47 celebrations than on the earlier holiday in the month celebrating
the country's independence.
In 1847, a group of Mormon pioneers, led by Brigham Young,
headed out on a journey across the land with covered wagons and
handcarts, determined to make a life in the west. They began the
journey because they were suffering religious persecution where they
were living in Nauvoo, Illinois. It is said that as Brigham Young gazed
out on the Salt Lake Valley on July 24, 1847, he proclaimed "This is
the Place".
To make it through their first, most critical winter, they
immediately planted crops so they could survive the winter, since they
were all alone with no supplies or established trade route. They were
inundated by a plague of crickets which started eating the crops and
threatened thier survival. But just when hope seemed gone, the seagulls
swarmed in and ate the crickets. It was proclaimed that the miracle was
an act of God, and the seagull was designated the state bird.
The Mormon Pioneers, who originally named the area we now know
as Utah, "Deseret", but the name was changed when they joined with the
other states in the union and the state was officially named Utah.
For the 150 year anniversary (in 1997), a group of people made
the trek from Nauvoo to Salt Lake City with handcarts and covered
wagons and dressed in the traditional style.
David