The difference between Holiday and Holy Day
By Richard Carter, Jr.
holy day -- 1. a day, as a major religious festival, viewed as especially holy; 2. any of certain major religious feast days (such as Christmas) on which Roman Catholics are required, as on Sundays, to attend Mass and refrain from unnecessary physical work, commercial activity, etc.: in full, "holy day of obligation".
holiday
holiday -- 1. "HOLY DAY"; 2. a day of freedom from labor; day set aside for leisure and recreation; 3. [British] vacation; 4. a day set aside by law or custom for the suspension of business, usually in commemoration of some event.
Holiday is almost always used as it has no real religious context any more (and we here in America are big on being non-secular). In general, "holy day" is used only in a strictly religious context -- for example, when writing about church, or the laity. It can get confusing in regards to those holidays which are holy days: Christmas, Chanukah, Easter, Rosh Hashana etc.
Some examples:
"While our young people are no doubt looking for to the school holiday,
let's not forget that they are getting this holiday because Yom Kippur is
actually a holy day," said the Rabbi to the congregation. (A confusing
example of both contexts being used in one sentence.)
"Christmas is one of our most important holy days," said the Priest to the
parishoner. (This is an example of the religious context.)
"Don't forget to get your presents for the Christmas holiday season,"
blared the store intercom. (An example of the public context.)
"Christmas is my favorite holiday," said by children all over the world.
(Again, a reference to Christmas in a context other than it's religious
meaning.)
Confused, yet?