The WP date field is not a post meta field. The only think that could interfere is another meta field named “date”
It is almost always better to use names that you know will be unique.
There isn’t any way that currently exists that will let you automatically update all the fields if you change the field name. This would be additionally problematic in this case if there is another field using the same name since you wouldn’t know what one to change in the database.
