As a course lecturer, should I excuse late assignment submissions if I wrote the assignment deadline slightly wrong? I am the course lecturer of an undergraduate course.
For a recent assignment, I had written the assignment deadline as 23 November 2018 (Saturday). Unfortunately, 23 November is actually a Friday, and not a Saturday.

I received an email from a student asking for me to excuse his/her assignment which was submitted late. The student explained that he/she marked the deadline as Saturday, without checking the assignment date.

Question

Should I excuse the student's late submission because I made a slight mistake in specifying the assignment deadline?

Note: We use a learning management system to receive assignment submissions, and the assignment deadline was entered correctly in the learning management system.

What I decided to do

For the current incident:
After reading the answers, and thinking it through, I decided that it is better to use the later of the two deadlines (i.e., 24 November Saturday) as the official deadline for the assignment.
I did make a mistake in writing the wrong day of the week for the deadline,
and students could have been misled with my mistake.
It is not fair to punish such students for my mistake.

For future courses:


The more places I put the deadline in
(e.g., the syllabus, the assignment itself, the learning management system),
it becomes likely that I will make a mistake somewhere.
In the future, I will put the deadline in only the learning management system, and refer students to check the deadlines there.
If the assignment deadline was not shown correctly to the students, then it is your error and they cannot be penalized for being late.

Claiming it is correct in one area while incorrect in another does not absolve you, you caused the confusion so you have to accept late submissions, as long as they arrived on Saturday...

Any submissions on Sunday will, of course, be late.

Re-reading this, it sounds a bit blunt... Probably because I have done exactly the same and had to sort it out after... Peace reigns if you stick to being fair, so giving them the extra time does not usually make much of a difference, except for the recognition from the students.