This field should be at the Work (formerly, Title) level.
The data in the current Date of First Performance field IS the display data. That's why for, e.g., The Roman Actor, the field has "1626 [licensed for stage, Oct 11]." That is Display data.
So the current Date of First Performance field should be renamed "Date of First Performance (Annals) (Display)"
The new field "Date of First Performance (Annals)" should be supplied with data from the old database-- the field will have "Date of First Performance Sort" or something like that as the title. It's the same data but turned into an integer so it can be searched.
This field should be at the Work (formerly, Title) level.
The data in the current Date of First Performance field IS the display data. That's why for, e.g., The Roman Actor, the field has "1626 [licensed for stage, Oct 11]." That is Display data.
So the current Date of First Performance field should be renamed "Date of First Performance (Annals) (Display)"
The new field "Date of First Performance (Annals)" should be supplied with data from the old database-- the field will have "Date of First Performance Sort" or something like that as the title. It's the same data but turned into an integer so it can be searched.