Dates can be anything at all from 1934 through to 2023 (for example) - no way of validating dates, I.e. Between dates, in the future, in the past etc etc
If you have a new starter form, or a any other form with a date field, it should be possible to restrict the date value being entered.
Also, it is not always necessary to enter a time as well as a date - should be an option just for a date field.
