GEDCOM date‑constraint semantics should not be propagated into Gramps

[ztlxltl]

I just want to make sure that everyone in this discussion is aware that the definitions of GEDCOM’s AFT and BEF changed with GEDCOM 7.0. In last August, I wrote the following summary. Please refer to the links for further background info.

@ztlxltl

Modified summary taken from here:

• GEDCOM 5.5.1 (PDF) defined:
  AFT = Event happened after the given date.
  BEF = Event happened before the given date.
  This is exclusive and uses the meaning of the words “after” and “before” so the UI matches the standard.
• GEDCOM 7.0 (PDF, HTML) has modified the definition to:
  AFT x = Exact date unknown, but no earlier than x.
  BEF x = Exact date unknown, but no later than x.
  This is inclusive.
• FROM and TO are inclusive in both versions and match the meaning of the words and therfore the UI.

This discussion seems to be based on the phrases “no earlier than” and “no later than” which are used in the GEDCOM 7.0 standard, not in the 5.5.1 standard. Gramps currently doesn’t support GEDCOM 7.0 (please correct me if my state of knowledge is outdated) and was built around the definitions in GEDCOM versions before the change of the meaning of AFT and BEF.

I likely don’t have the time to participate in this discussion in-depth. In my opinion, the logical meaning (in Gramps’ documentation/data field definition, code e.g. for comparison/filters, etc.) should be the same as the meaning of the words in the UI (this is important when translating). GEDCOM exporters and importers should deal with the correct processing according to the GEDCOM version used.