Is there a list with common mistakes in database entries?
Microsoft Excel has a nasty habit of thinking it knows your data better than you do, and when it sees gene names like Mar3 and Sept7, it tries to be helpful and convert them to dates.

So anytime someone puts a long gene list in to Excel and takes it back out again, you see those genes and their relatives converted to dates.

This has been known for years, but you still see it in lots and lots of published papers.

According to http://dx.doi.org/10.1186/s13059-016-1044-7, almost 20% of article supplementary material gene lists made with Excel contain such errors.