special days used in calendar.unitedkingdom not recognised

[Steven Wilson]

Description: Ubuntu 14.04.2 LTS
Release: 14.04

bsdmainutils:
  Installed: 9.0.5ubuntu1

calendar.unitedkingdom uses names for special days:

MarEquinox Vernal Equinox
JunSolstice Summer Solstice (longest day of the year)
SepEquinox Autumnal Equinox
DecSolstice Winter Solstice (shortest day of the year)

It seems these aren't recognised and the entries are being compiled to the 1st of each month. Using the following command:

$ calendar -t 20150301 -f /usr/share/calendar/calendar.unitedkingdom

I'd expect the output:

Mar 01 Saint David's day (Wales)

But what I get is:

Mar 01 Vernal Equinox
Mar 01 Saint David's day (Wales)