Is it fine to cancel class on days before national holidays, due to low attendance? So, thanksgiving break is coming up. On my campus, a large portion of the students leave early Wednesday to get back home. The break doesn't officially start until Thursday, but since that is the holiday the students (understandably) leave earlier.

I teach on Wednesdays (among other days). I had forgotten about this poor attendance when I planned my syllabus and am currently planning to teach new material next Wednesday.

Now, I anticipate about 75% of the class (50 total students) will be absent. They knew I would be teaching new material that day, since it was on the syllabus.

Do I cancel class so that the majority of students don't miss a lecture? Do I hold class but post my lecture notes so that the students who missed could (theoretically, at least) make up the work they missed on their own?

If I cancel class, I could shift around material so that nothing is lost (by moving a review day). However, something feels "wrong" about cancelling a class that the university has scheduled to occur because the students decided they wanted to start their vacation early.

Is it fine to cancel a class because you don't expect many students to attend?
I have known a number of professors who took a third approach: on an expected low-attendance class day such as the day before Thanksgiving, they held a lecture, but did not make it part of the "standard" curriculum.  Instead, they would schedule some sort of fun and exciting "bonus material," like a notable guest speaker or a cool demonstration.  That way, those students who showed up got something out of coming, but the ones whose plans prevented them from being there didn't have any missed "core" material to make up.