On a point of fact,
FH has always used, and still uses, the
GEDCOM standard
Date qualifiers
ABT=Approximate,
CAL=Calculated, and
EST=Estimated, and if you open its
Date Entry Assistant those three
Qualifiers are still offered.
It is only
Approximate that is now displayed as
Circa in
FH V6.
As it needs to be
100% GEDCOM compliant, FH can only offer those three
Qualifiers.
However, I do have concerns about
Circa prior to a
Date instead of
Approx after the
Date as explained in
V6 circa Date format (11932).
It would be useful to have a
Preference to choose between
Circa and
Approx.
[EDIT: This preference has now been added to V6.0.3 in
Tools > Preferences > General so this request can be closed.]
I am not sure there is much to support the idea that
about,
approx, and
circa have different meanings. Wikipedia says:
Circa (from Latin, meaning "around, about"), usually abbreviated c., ca or ca. (also circ. or cca.), means "approximately" in English, French, Catalan[1], Spanish, Italian, Croatian, Serbian, German, Dutch, Romanian, Slovak, Slovene, Czech, Bulgarian, Icelandic, Norwegian, Swedish, Danish (spelled cirka), and Estonian, usually referring to a date.[2] Circa is widely used in genealogy and historical writing when the dates of events are not accurately known.
Most dictionary definitions seem to say much the same.
Furthermore, the extent of the approximation is indicated by the precision of the Date.
e.g.
circa 1 Jan 1900 suggests within a few days or weeks of 1 Jan 1900
circa Jan 1900 suggests within several months of Jan 1900
circa 1900 suggests within a few years or decades of 1900