Oh, what I meant was this:
In the “Year” field, but both years, e.g.,
[1894] 1997
And in the “Custom 8” field, put only the original date, e.g.:
1894
For those entries that only have one year, the “Custom 8” field should be a repeat of what was put in the “Year” field. That does mean that for all new entries, regardless of if there is one or two years, all entries will have to have something in the “Year” field and the “Custom 8” field. That’s the downside to that solution. The upside is that this system will not break the sort order when an additional work is added to the EndNote bibliography.