Memorial Day was moved from May 30 to the last Monday of May so it always falls on a Monday. Likewise with Columbus Day, which was moved from October 12 to the second Monday of October. Thanksgiving was moved from the last Thursday of November (between Nov. 24 and Nov. 30 inclusive) to the 4th Thursday of November (between Nov. 22 and Nov. 28 inclusive) to make the Christmas shopping season longer. The name of Armistice Day was changed to Veterans Day.
US holidays?
Holiday past means holidays that have happened before. Holiday present means the current holidays. The ones that are happening right now.
during summer holidays is a time within the summer holidays, and summer holidays are summer holidays altogether.
There are about 45 holidays in the USA
57 holidays
The french get more and longer holidays
There are many holidays not celebrated in the US. The Queen's Birthday, ANZAC day and Australia Day are just three of many holidays not celebrated or recognised in the US.
The correct saying is "Happy Holidays", now you know
I think the USA has a few unnecessary holidays...
Thanksgiving, and Christmas, are both holidays that are nationally recognized in the US.
Monday
You can find information about US holidays and which businesses will be closed on these holidays on the Wikipedia page called "Public Holidays in the United States". The page has a table organizing the data by date order.