If you put a date with year 1901 or older in a date field- including entry date- it won't validate and you can't save it.

Summarizing: You can't have dates prior to 1901 or after 2038. This is the size limitation of int data types that we use for date columns.

2 possible solutions:

• allow changing column type from int to bigint same as we do for RTE fields. This is quick and easy, because we have the code already
• start using datetime column instead of int for dates. This is IMO the most proper solution and this how it should have been done 15 years ago, but making the change will be more involved.